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Exponents-negative-and-fractional/145607: 7x^-8 * 6x^3
1 solutions

Answer 106256 by jim_thompson5910(28593) About Me  on 2008-06-17 17:24:05 (Show Source):
You can put this solution on YOUR website!
%287x%5E%28-8%29%29%2A%286x%5E3%29 Start with the given expression


42x%5E%28-8%29%2Ax%5E%283%29 Multiply the coefficients 7 and 6 to get 42


42x%5E%28-8%2B3%29 When you multiply monomials, simply add the exponents


42x%5E%28-5%29 Add


So our answer is 42x%5E%28-5%29


Linear-equations/145603: Megan’s verbal and math scores
on the SAT was 1094. Her math
score was 248 points higher
than her verbal score. What were
her math and verbal SAT scores?

1 solutions

Answer 106254 by jim_thompson5910(28593) About Me  on 2008-06-17 16:59:17 (Show Source):
You can put this solution on YOUR website!
Let x=verbal score and y=math score

"Megan’s verbal and math scores on the SAT was 1094" translates to x%2By=1094

"Her math score was 248 points higher than her verbal score" translates to y=x%2B248


Start with the given system
x%2By=1094
y=x%2B248



x%2B%28x%2B248%29=1094 Plug in y=x%2B248 into the first equation. In other words, replace each y with x%2B248. Notice we've eliminated the y variables. So we now have a simple equation with one unknown.


2x%2B248=1094 Combine like terms on the left side


2x=1094-248Subtract 248 from both sides


2x=846 Combine like terms on the right side


x=%28846%29%2F%282%29 Divide both sides by 2 to isolate x



x=423 Divide




Now that we know that x=423, we can plug this into y=x%2B248 to find y



y=%28423%29%2B248 Substitute 423 for each x


y=671 Simplify


So our answers are x=423 and y=671



So the verbal score was 423 and the math score was 671.


Rational-functions/145600: divide the following expression:
(x^2+10x+21) / (x+7)
A) x^2+3
B) x-2
C) x+5
D) x+3
1 solutions

Answer 106253 by jim_thompson5910(28593) About Me  on 2008-06-17 16:50:18 (Show Source):
You can put this solution on YOUR website!

%28x%5E2%2B10x%2B21%29%2F%28x%2B7%29 Start with the given expression.


%28%28x%2B7%29%2A%28x%2B3%29%29%2F%28x%2B7%29 Factor x%5E2%2B10x%2B21 to get %28x%2B7%29%2A%28x%2B3%29.


%28highlight%28x%2B7%29%28x%2B3%29%29%2F%28highlight%28x%2B7%29%29 Highlight the common terms.


%28cross%28x%2B7%29%28x%2B3%29%29%2F%28cross%28x%2B7%29%29 Cancel out the common terms.


x%2B3 Simplify.


So %28x%5E2%2B10x%2B21%29%2F%28x%2B7%29 simplifies to x%2B3.


In other words, %28x%5E2%2B10x%2B21%29%2F%28x%2B7%29=x%2B3 where x%3C%3E-7


Coordinate-system/145602: graph the following equations
y=-1/3x + 4
3y-9x=30
1 solutions

Answer 106252 by jim_thompson5910(28593) About Me  on 2008-06-17 16:47:49 (Show Source):
You can put this solution on YOUR website!
# 1



Looking at y=-%281%2F3%29x%2B4 we can see that the equation is in slope-intercept form y=mx%2Bb where the slope is m=-1%2F3 and the y-intercept is b=4


Since b=4 this tells us that the y-intercept is .Remember the y-intercept is the point where the graph intersects with the y-axis

So we have one point




Now since the slope is comprised of the "rise" over the "run" this means
slope=rise%2Frun

Also, because the slope is -1%2F3, this means:

rise%2Frun=-1%2F3


which shows us that the rise is -1 and the run is 3. This means that to go from point to point, we can go down 1 and over 3



So starting at , go down 1 unit


and to the right 3 units to get to the next point



Now draw a line through these points to graph y=-%281%2F3%29x%2B4

So this is the graph of y=-%281%2F3%29x%2B4 through the points and








# 2

3y-9x=30 Start with the given equation



3y=30%2B9x Add 9+x to both sides


3y=%2B9x%2B30 Rearrange the equation


y=%28%2B9x%2B30%29%2F%283%29 Divide both sides by 3


y=%28%2B9%2F3%29x%2B%2830%29%2F%283%29 Break up the fraction


y=3x%2B10 Reduce





Looking at y=3x%2B10 we can see that the equation is in slope-intercept form y=mx%2Bb where the slope is m=3 and the y-intercept is b=10


Since b=10 this tells us that the y-intercept is .Remember the y-intercept is the point where the graph intersects with the y-axis

So we have one point




Now since the slope is comprised of the "rise" over the "run" this means
slope=rise%2Frun

Also, because the slope is 3, this means:

rise%2Frun=3%2F1


which shows us that the rise is 3 and the run is 1. This means that to go from point to point, we can go up 3 and over 1



So starting at , go up 3 units


and to the right 1 unit to get to the next point



Now draw a line through these points to graph y=3x%2B10

So this is the graph of y=3x%2B10 through the points and


Linear-equations/145582: I need help with this math homework problem It says solve the linear equation using the substitution method:

x=8-4y
3x+5y=3

1 solutions

Answer 106246 by jim_thompson5910(28593) About Me  on 2008-06-17 16:01:54 (Show Source):
You can put this solution on YOUR website!

Start with the given system
3x%2B5y=3
x=8-4y



3%288-4y%29%2B5y=3 Plug in x=8-4y into the first equation. In other words, replace each x with 8-4y. Notice we've eliminated the x variables. So we now have a simple equation with one unknown.


24-12y%2B5y=3 Distribute


-7y%2B24=3 Combine like terms on the left side


-7y=3-24Subtract 24 from both sides


-7y=-21 Combine like terms on the right side


y=%28-21%29%2F%28-7%29 Divide both sides by -7 to isolate y



y=3 Divide




Now that we know that y=3, we can plug this into x=8-4y to find x



x=8-4%283%29 Substitute 3 for each y


x=-4 Simplify


So our answer is x=-4 and y=3 which also looks like



Notice if we graph the two equations, we can see that their intersection is at . So this verifies our answer.


+graph%28+500%2C+500%2C+-5%2C+5%2C+-5%2C+5%2C+%283-3x%29%2F5%2C+%28x-8%29%2F%28-4%29%29+ Graph of 3x%2B5y=3 (red) and x=8-4y (green)


Rational-functions/145589: Simplify the expression
12a^2+26a+12 / 6-5a-6a^2
A) 2(6a^2+13a+6) / -(6a^2+5a-5)
B)-2
C)-2(3a+2) / (3a-2)
D) 2(3a+2) / (3a-2)
1 solutions

Answer 106245 by jim_thompson5910(28593) About Me  on 2008-06-17 16:00:23 (Show Source):
You can put this solution on YOUR website!

%2812a%5E2%2B26a%2B12%29%2F%286-5a-6a%5E2%29 Start with the given expression.


%282%2A%282%2Aa%2B3%29%2A%283%2Aa%2B2%29%29%2F%286-5a-6a%5E2%29 Factor 12a%5E2%2B26a%2B12 to get 2%2A%282%2Aa%2B3%29%2A%283%2Aa%2B2%29.


%282%2A%282%2Aa%2B3%29%2A%283%2Aa%2B2%29%29%2F%28-%282%2Aa%2B3%29%2A%283%2Aa-2%29%29 Factor 6-5a-6a%5E2 to get -%282%2Aa%2B3%29%2A%283%2Aa-2%29.


Highlight the common terms.


-%28%282%29cross%282%2Aa%2B3%29%283%2Aa%2B2%29%29%2F%28cross%282%2Aa%2B3%29%283%2Aa-2%29%29 Cancel out the common terms.


-%282%283%2Aa%2B2%29%29%2F%28%283%2Aa-2%29%29 Simplify.


So %2812a%5E2%2B26a%2B12%29%2F%286-5a-6a%5E2%29 simplifies to -%282%283%2Aa%2B2%29%29%2F%28%283%2Aa-2%29%29.


In other words, %2812a%5E2%2B26a%2B12%29%2F%286-5a-6a%5E2%29=-%282%283%2Aa%2B2%29%29%2F%28%283%2Aa-2%29%29 where a%3C%3E-3%2F2 or a%3C%3E2%2F3


So the answer is choice C


Rational-functions/145591: Perform the indicated operations and simplify the following expression:
x+6/x^2-16 * 3x-12/3x+18
A) 0
B) 3 / 3(x+4)
C) 1/x+4
D) -1/x+4
1 solutions

Answer 106244 by jim_thompson5910(28593) About Me  on 2008-06-17 15:57:09 (Show Source):
You can put this solution on YOUR website!
%28%28x%2B6%29%2F%28x%5E2-16%29%29%28%283x-12%29%2F%283x%2B18%29%29 Start with the given expression.



%28%28x%2B6%29%2F%28%28x-4%29%2A%28x%2B4%29%29%29%28%283x-12%29%2F%283x%2B18%29%29 Factor x%5E2-16 to get %28x-4%29%2A%28x%2B4%29.


%28%28x%2B6%29%2F%28%28x-4%29%2A%28x%2B4%29%29%29%28%283%28x-4%29%29%2F%283x%2B18%29%29 Factor 3x-12 to get 3%28x-4%29.


%28%28x%2B6%29%2F%28%28x-4%29%2A%28x%2B4%29%29%29%28%283%28x-4%29%29%2F%283%28x%2B6%29%29%29 Factor 3x%2B18 to get 3%28x%2B6%29.


%283%28x%2B6%29%28x-4%29%29%2F%283%28x-4%29%28x%2B4%29%28x%2B6%29%29 Combine the fractions.


Highlight the common terms.


Cancel out the common terms.


%281%29%2F%28%28x%2B4%29%29 Simplify.


So %28%28x%2B6%29%2F%28x%5E2-16%29%29%28%283x-12%29%2F%283x%2B18%29%29 simplifies to %281%29%2F%28%28x%2B4%29%29.


In other words, where x%3C%3E-4,x%3C%3E4, or x%3C%3E-6



So the answer choice is C


Inequalities/145588: Please help me with this problem Thanks it says solve the following inequal. show a number line as your solution and give the interval notation for the solution

5x-9>2x-7


5[3m-(m+4)]<-2(m-4) same directions as the first thanks again!!
1 solutions

Answer 106228 by jim_thompson5910(28593) About Me  on 2008-06-17 14:17:39 (Show Source):
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5x-9%3E2x-7 Start with the given inequality



5x%3E2x-7%2B9Add 9 to both sides


5x-2x%3E-7%2B9 Subtract 2x from both sides


3x%3E-7%2B9 Combine like terms on the left side


3x%3E2 Combine like terms on the right side


x%3E%282%29%2F%283%29 Divide both sides by 3 to isolate x



x%3E2%2F3 Reduce

--------------------------------------------------------------
Answer:
So our answer is x%3E2%2F3 (which is approximately x%3E0.667 in decimal form)




So the answer in interval notation is


Here's the graph of the solution set











5%283m-%28m%2B4%29%29%3C-2%28m-4%29+ Start with the given inequality


15m-5%28m%2B4%29%3C-2%28m-4%29+ Distribute




15m-5m-20%3C-2m%2B8 Distribute


10m-20%3C-2m%2B8 Combine like terms on the left side


10m%3C-2m%2B8%2B20Add 20 to both sides


10m%2B2m%3C8%2B20 Add 2m to both sides


12m%3C8%2B20 Combine like terms on the left side


12m%3C28 Combine like terms on the right side


m%3C%2828%29%2F%2812%29 Divide both sides by 12 to isolate m



m%3C7%2F3 Reduce

--------------------------------------------------------------
Answer:
So our answer is m%3C7%2F3 (which is approximately m%3C2.333 in decimal form)



So the answer in interval notation is




Here's the graph of the solution set








Matrices-and-determiminant/145533: This question is from textbook finite mathematics
Use the Gauss-Jordan method to solve each system of equations.
3x-6y+3z=11
2x-y+z=-9
5x-5y+2z=18
I know how to change it into matrix form but then what?
1 solutions

Answer 106217 by jim_thompson5910(28593) About Me  on 2008-06-17 12:54:38 (Show Source):
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This solution was generated from the linear algebra toolkit


Photobucket



So x=-1%2F2, y=-73%2F6 and z=-121%2F6


Rational-functions/145529: i need to find the asymptotes of the rational function of
6x^2/2x^2+5x+2
1 solutions

Answer 106182 by jim_thompson5910(28593) About Me  on 2008-06-16 21:00:21 (Show Source):
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y=%286x%5E2%29%2F%282x%5E2%2B5x%2B2%29%29 Start with the given function



Looking at the numerator 6x%5E2, we can see that the degree is 2 since the highest exponent of the numerator is 2. For the denominator 2x%5E2%2B5x%2B2, we can see that the degree is 2 since the highest exponent of the denominator is 2.


Horizontal Asymptote:
Since the degree of the numerator and the denominator are the same, we can find the horizontal asymptote using this procedure:

To find the horizontal asymptote, first we need to find the leading coefficients of the numerator and the denominator.

Looking at the numerator 6x%5E2, the leading coefficient is 6

Looking at the denominator 2x%5E2%2B5x%2B2, the leading coefficient is 2

So the horizontal asymptote is the ratio of the leading coefficients. In other words, simply divide 6 by 2 to get %286%29%2F%282%29=3


So the horizontal asymptote is y=3





--------------------------------------------------



Vertical Asymptote:
To find the vertical asymptote, just set the denominator equal to zero and solve for x

2x%5E2%2B5x%2B2=0 Set the denominator equal to zero


Now let's use the quadratic formula to solve for x. If you need help with the quadratic formula, check out this solver.

After using the quadratic formula, we get the solutions
x=-1%2F2 or x=-2

So this means the vertical asymptotes are x=-1%2F2 or x=-2

Notice if we graph y=%286x%5E2%29%2F%282x%5E2%2B5x%2B2%29, we can visually verify our answers:

Graph of y=%286x%5E2%29%2F%282x%5E2%2B5x%2B2%29%29 with the horizontal asymptote y=3 (blue line) and the vertical asymptotes x=-1%2F2 and x=-2 (green lines)

note: for some reason the graph didn't format correctly, but you get the idea. This should look better on a graphing calculator.


Polynomials-and-rational-expressions/145526: Using Rational Zero Theorem- Find all rational zeros of the polynomial
8x^3-10x^2-17x+10
1 solutions

Answer 106175 by jim_thompson5910(28593) About Me  on 2008-06-16 20:43:17 (Show Source):
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Any rational zero can be found through this equation

where p and q are the factors of the last and first coefficients


So let's list the factors of 10 (the last coefficient):



Now let's list the factors of 8 (the first coefficient):



Now let's divide each factor of the last coefficient by each factor of the first coefficient









Now simplify

These are all the distinct rational zeros of the function that could occur





logarithm/145525: I need help solving this logarithmic equation:
log(x-1)+log(x+2)=2
1 solutions

Answer 106174 by jim_thompson5910(28593) About Me  on 2008-06-16 20:42:31 (Show Source):
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log%2810%2C%28x-1%29%29%2Blog%2810%2C%28x%2B2%29%29=2 Start with the given equation


log%2810%2C%28%28x-1%29%28x%2B2%29%29%29=2 Combine the logs using the identity log%28b%2C%28A%29%29%2Blog%28b%2C%28B%29%29=log%28b%2C%28A%2AB%29%29



log%2810%2C%28x%5E2%2Bx-2%29%29=2 Foil


10%5E2=x%5E2%2Bx-2 Rewrite the equation using the property: log%28b%2C%28x%29%29=y ====> b%5Ey=x


100=x%5E2%2Bx-2 Square 10 to get 100


0=x%5E2%2Bx-102 Subtract 100 from both sides


Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%281%29+%2B-+sqrt%28+%281%29%5E2-4%281%29%28-102%29+%29%29%2F%282%281%29%29 Plug in a=1, b=1, and c=-102


x+=+%28-1+%2B-+sqrt%28+1-4%281%29%28-102%29+%29%29%2F%282%281%29%29 Square 1 to get 1.


x+=+%28-1+%2B-+sqrt%28+1--408+%29%29%2F%282%281%29%29 Multiply 4%281%29%28-102%29 to get -408


x+=+%28-1+%2B-+sqrt%28+1%2B408+%29%29%2F%282%281%29%29 Rewrite sqrt%281--408%29 as sqrt%281%2B408%29


x+=+%28-1+%2B-+sqrt%28+409+%29%29%2F%282%281%29%29 Add 1 to 408 to get 409


x+=+%28-1+%2B-+sqrt%28+409+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-1%2Bsqrt%28409%29%29%2F%282%29 or x+=+%28-1-sqrt%28409%29%29%2F%282%29 Break up the expression.


So the possible answers are x+=+%28-1%2Bsqrt%28409%29%29%2F%282%29 or x+=+%28-1-sqrt%28409%29%29%2F%282%29

However, since you cannot take the log of a negative number, this means that the only answer is

x+=+%28-1%2Bsqrt%28409%29%29%2F%282%29



-------------------------------
Answer:


So our answer is x+=+%28-1%2Bsqrt%28409%29%29%2F%282%29 which approximates to x=9.612


Linear_Algebra/145524: I am working with Inverse functions and need help find (f(g))(x) and (g(f))(x) given f(x)=log(2)x g(x)=2 to x power
sorry if that is written confusing.. on paper the 2 after log is lowered
1 solutions

Answer 106173 by jim_thompson5910(28593) About Me  on 2008-06-16 20:36:00 (Show Source):
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Let's evaluate f(g(x))

f%28x%29=log%282%2C%28x%29%29 Start with the first function


f%28g%28x%29%29=log%282%2C%282%5Ex%29%29 Plug in g%28x%29=2%5Ex


f%28g%28x%29%29=x%2Alog%282%2C%282%29%29 Rewrite the right side using the identity log%28b%2C%28x%5Ey%29%29=y%2Alog%28b%2C%28x%29%29


f%28g%28x%29%29=x%2A1 Take the log base 2 of 2 to get 1. Note: log%28x%2C%28x%29%29=1


f%28g%28x%29%29=x Multiply



------------------------



Let's evaluate g(f(x))

g%28x%29=2%5Ex Start with the second function


g%28f%28x%29%29=2%5E%28log%282%2C%28x%29%29%29 Plug in f%28x%29=log%282%2C%28x%29%29



Let y=log%282%2C%28x%29%29. So this means that 2%5Ey=x by use of the property log%28b%2C%28x%29%29=y ====> b%5Ey=x


g%28f%28x%29%29=2%5Ey Replace log%282%2C%28x%29%29 with "y"


g%28f%28x%29%29=x Now replace 2%5Ey with "x"




So both f(g(x)) and g(f(x)) equal x.


Rational-functions/145523: I need help when asked to find asymptotes of a rational function. For example:
f(x)=x+2
------
x sqrd-5x+6
1 solutions

Answer 106171 by jim_thompson5910(28593) About Me  on 2008-06-16 20:22:03 (Show Source):
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y=%28x%2B2%29%2F%28x%5E2-5x%2B6%29%29 Start with the given function



Looking at the numerator x%2B2, we can see that the degree is 1 since the highest exponent of the numerator is 1. For the denominator x%5E2-5x%2B6, we can see that the degree is 2 since the highest exponent of the denominator is 2.


Horizontal Asymptote:

Since the degree of the numerator (which is 1) is less than the degree of the denominator (which is 2), the horizontal asymptote is always y=0

So the horizontal asymptote is y=0



--------------------------------------------------



Vertical Asymptote:
To find the vertical asymptote, just set the denominator equal to zero and solve for x

x%5E2-5x%2B6=0 Set the denominator equal to zero


Now let's use the quadratic formula to solve for x. If you need help with the quadratic formula, check out this solver.

After using the quadratic formula, we get the solutions
x=3 or x=2

So this means the vertical asymptotes are x=3 or x=2

Notice if we graph y=%28x%2B2%29%2F%28x%5E2-5x%2B6%29, we can visually verify our answers:

Graph of y=%28x%2B2%29%2F%28x%5E2-5x%2B6%29%29 with the horizontal asymptote y=0 (blue line) and the vertical asymptotes x=3 and x=2 (green lines)



Quadratic_Equations/145522: x^2+7x+10=0
3x^2-6x=0
1 solutions

Answer 106168 by jim_thompson5910(28593) About Me  on 2008-06-16 20:09:27 (Show Source):
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I'm assuming you want to solve for x. I'll solve the first one to get you started.


# 1




x%5E2%2B7x%2B10=0 Start with the given equation.


Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%287%29+%2B-+sqrt%28+%287%29%5E2-4%281%29%2810%29+%29%29%2F%282%281%29%29 Plug in a=1, b=7, and c=10


x+=+%28-7+%2B-+sqrt%28+49-4%281%29%2810%29+%29%29%2F%282%281%29%29 Square 7 to get 49.


x+=+%28-7+%2B-+sqrt%28+49-40+%29%29%2F%282%281%29%29 Multiply 4%281%29%2810%29 to get 40


x+=+%28-7+%2B-+sqrt%28+9+%29%29%2F%282%281%29%29 Subtract 40 from 49 to get 9


x+=+%28-7+%2B-+sqrt%28+9+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-7+%2B-+3%29%2F%282%29 Take the square root of 9 to get 3.


x+=+%28-7+%2B+3%29%2F%282%29 or x+=+%28-7+-+3%29%2F%282%29 Break up the expression.


x+=+%28-4%29%2F%282%29 or x+=++%28-10%29%2F%282%29 Combine like terms.


x+=+-2 or x+=+-5 Simplify.


So our answers are x+=+-2 or x+=+-5



Quadratic_Equations/145521: If f(x)=2x^2-7x+3 find f(2) and find f(-3)
1 solutions

Answer 106167 by jim_thompson5910(28593) About Me  on 2008-06-16 20:08:21 (Show Source):
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# 1


f%28x%29=2x%5E2-7x%2B3 Start with the given function


f%282%29=2%282%29%5E2-7%282%29%2B3 Plug in x=2


f%282%29=2%2A4-7%2A2%2B3 Raise 2 to the 2nd power to get 4


f%282%29=8-7%2A2%2B3 Multiply 2 and 4 to get 8


f%282%29=8-14%2B3 Multiply 7 and 2 to get 14


f%282%29=-6%2B3 Subtract 14 from 8 to get -6


f%282%29=-3 Add -6 and 3 to get -3




----------------------------------------------------------------------


# 2

f%28x%29=2x%5E2-7x%2B3 Start with the given function


f%28-3%29=2%28-3%29%5E2-7%28-3%29%2B3 Plug in x=-3


f%28-3%29=2%2A9-7%2A-3%2B3 Raise -3 to the 2nd power to get 9


f%28-3%29=18-7%2A-3%2B3 Multiply 2 and 9 to get 18


f%28-3%29=18--21%2B3 Multiply 7 and -3 to get -21


f%28-3%29=39%2B3 Subtract -21 from 18 to get 39


f%28-3%29=42 Add 39 and 3 to get 42



Equations/145507: solve for y: 2/3y+k=j
1 solutions

Answer 106155 by jim_thompson5910(28593) About Me  on 2008-06-16 17:38:51 (Show Source):
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%282%2F3%29y%2Bk=j Start with the given equation


%282%2F3%29y=j-k Subtract k from both sides


cross%28%283%2F2%29%282%2F3%29%29y=%283%2F2%29%28j-k%29 Multiply both sides by 3%2F2



So our answer is y=%283%2F2%29%28j-k%29


Expressions-with-variables/145505: 16 2(x-4)
--- + ------
x2-16 x+4
Adding Rational Expressions
1 solutions

Answer 106153 by jim_thompson5910(28593) About Me  on 2008-06-16 17:36:57 (Show Source):
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%2816%29%2F%28x%5E2-16%29%2B%282%28x-4%29%29%2F%28x%2B4%29 Start with the given expression


%2816%29%2F%28%28x%2B4%29%28x-4%29%29%2B%282%28x-4%29%29%2F%28x%2B4%29 Factor x%5E2-16 to get %28x%2B4%29%28x-4%29. So the LCD is %28x%2B4%29%28x-4%29


Multiply the second fraction by %28x-4%29%2F%28x-4%29


Combine the fractions



%2816%29%2F%28x%5E2-16%29%2B%282%28x-4%29%28x-4%29%29%2F%28x%5E2-16%29 Foil %28x%2B4%29%28x-4%29 to get x%5E2-16


%2816%29%2F%28x%5E2-16%29%2B%282%28x%5E2-8x%2B16%29%29%2F%28x%5E2-16%29 Foil %28x-4%29%28x-4%29 to get x%5E2-8x%2B16


%2816%29%2F%28x%5E2-16%29%2B%282x%5E2-16x%2B32%29%2F%28x%5E2-16%29 Distribute


%28%2816%29%2B%282x%5E2-16x%2B32%29%29%2F%28x%5E2-16%29 Since the two fractions have the same denominator, this means we can combine them.


%282x%5E2-16x%2B48%29%2F%28x%5E2-16%29 Combine like terms


So %2816%29%2F%28x%5E2-16%29%2B%282%28x-4%29%29%2F%28x%2B4%29 simplifies to %282x%5E2-16x%2B48%29%2F%28x%5E2-16%29.


In other words, where x%3C%3E-4 or x%3C%3E4


Graphs/145490: What is the domain and range for the following equations:
y=1-x
y=|1-x|
y=1-x^2

1 solutions

Answer 106148 by jim_thompson5910(28593) About Me  on 2008-06-16 16:52:59 (Show Source):
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# 1
D: all real numbers
R: all real numbers



# 2
D: all real numbers
R: y%3E=1


# 3
D: all real numbers
R: y%3C=1


Exponential-and-logarithmic-functions/145504: How do you Plot the graphs of the following functions

1. (x)=6x
2. f(x)=3x - 2
3. f(x)=(1/2)x
4. f(x)= log2x

1 solutions

Answer 106146 by jim_thompson5910(28593) About Me  on 2008-06-16 16:50:45 (Show Source):
You can put this solution on YOUR website!
I'll do the first two to get you started

# 1



Looking at y=6x we can see that the equation is in slope-intercept form y=mx%2Bb where the slope is m=6 and the y-intercept is b=0 note: y=6x really looks like y=6x%2B0


Since b=0 this tells us that the y-intercept is .Remember the y-intercept is the point where the graph intersects with the y-axis

So we have one point




Now since the slope is comprised of the "rise" over the "run" this means
slope=rise%2Frun

Also, because the slope is 6, this means:

rise%2Frun=6%2F1


which shows us that the rise is 6 and the run is 1. This means that to go from point to point, we can go up 6 and over 1



So starting at , go up 6 units


and to the right 1 unit to get to the next point



Now draw a line through these points to graph y=6x

So this is the graph of y=6x through the points and








# 2



Looking at y=3x-2 we can see that the equation is in slope-intercept form y=mx%2Bb where the slope is m=3 and the y-intercept is b=-2


Since b=-2 this tells us that the y-intercept is .Remember the y-intercept is the point where the graph intersects with the y-axis

So we have one point




Now since the slope is comprised of the "rise" over the "run" this means
slope=rise%2Frun

Also, because the slope is 3, this means:

rise%2Frun=3%2F1


which shows us that the rise is 3 and the run is 1. This means that to go from point to point, we can go up 3 and over 1



So starting at , go up 3 units


and to the right 1 unit to get to the next point



Now draw a line through these points to graph y=3x-2

So this is the graph of y=3x-2 through the points and


Graphs/145489: This question is from textbook
graph the inequality y<3x+1.
1 solutions

Answer 106143 by jim_thompson5910(28593) About Me  on 2008-06-16 15:13:21 (Show Source):
You can put this solution on YOUR website!

y%3C3x%2B1 Start with the 1st inequality


y=3x%2B1 Replace the inequality sign with an equals sign


So in order to plot y%3C3x%2B1, we need to plot the equation y=3x%2B1 first


+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C3x%2B1%29+ Graph of y=3x%2B1


Now plug in a test point (0,0) into the inequality y%3C3x%2B1


0%3C3%2A%280%29%2B1 Plug in x=0 and y=0


0%3C1 Evaluate and simplify


Since the inequality is true, this means that we shade the entire region that contains the point (0,0). So this means that we shade everything below the line y=3x%2B1. Note: Since the inequality is a "less than" sign, this means that the line should be a dotted line.


Graph of y%3C3x%2B1 with the shaded region in green


Equations/145491: I can't seem to figure out this problem, can someone please help me?
1-2/x
-----
x-4/x
1 solutions

Answer 106142 by jim_thompson5910(28593) About Me  on 2008-06-16 15:09:32 (Show Source):
You can put this solution on YOUR website!
%281-2%2Fx%29%2F%28x-4%2Fx%29 Start with the given expression


%28x%281-2%2Fx%29%29%2F%28x%28x-4%2Fx%29%29 Multiply both the numerator and the denominator by the LCD x


Distribute. Notice how the inner denominators cancel


%28x-2%29%2F%28x%5E2-4%29 Simplify

%28x-2%29%2F%28%28x-2%29%2A%28x%2B2%29%29 Factor x%5E2-4 to get %28x-2%29%2A%28x%2B2%29.


%28highlight%28x-2%29%29%2F%28highlight%28x-2%29%28x%2B2%29%29 Highlight the common terms.


%28cross%28x-2%29%29%2F%28cross%28x-2%29%28x%2B2%29%29 Cancel out the common terms.


1%2F%28%28x%2B2%29%29 Simplify.


So %281-2%2Fx%29%2F%28x-4%2Fx%29 simplifies to 1%2F%28%28x%2B2%29%29.


In other words, %281-2%2Fx%29%2F%28x-4%2Fx%29=1%2F%28%28x%2B2%29%29 where x%3C%3E0, x%3C%3E-2, or x%3C%3E2


Inequalities/145493:
Can anyone please Solve the inequality 4x <12 than sketch the solution set on the real number line. Thank You

1 solutions

Answer 106141 by jim_thompson5910(28593) About Me  on 2008-06-16 15:03:18 (Show Source):
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4x%3C12 Start with the given inequality



x%3C%2812%29%2F%284%29 Divide both sides by 4 to isolate x



x%3C3 Divide

--------------------------------------------------------------
Answer:
So our answer is x%3C3



Here's the graph of the solution set


Note: at x=3 there is a open circle (which means this point is excluded)


Equations/145492: Any solutions to this problem? Thank You
Graph the following (< =means≤,less than or equal to)

-2 < =x <1
1 solutions

Answer 106140 by jim_thompson5910(28593) About Me  on 2008-06-16 15:01:47 (Show Source):
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Graph of -2%3C=x%3C1



Note: at x=-2 there is a closed circle (which means this point is included) and at x=1 there is a open circle (which means this point is excluded)


Graphs/145488: This question is from textbook
solve the inequality 4<-z-4<11. Give the result in set notation and graph it.
1 solutions

Answer 106139 by jim_thompson5910(28593) About Me  on 2008-06-16 14:58:46 (Show Source):
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4%3C-z-4%3C11 Start with the given inequality





8%3C-z%3C15 Add 4 to all sides






-8%3Ez%3E-15 Divide every side by -1 to isolate z. Remember, dividing every side of an inequality by a negative number flips the inequality signs




-15%3Cz%3C-8 Rearrange the inequality.


So the solution in interval notation is: (-15,-8)


The solution in set notation is


Now let's graph the solution set



Note: at z=-15 there is a open circle (which means this point is excluded) and at z=-8 there is a open circle (which means this point is excluded)





Radicals/145409: 30√11-6√11
1 solutions

Answer 106084 by jim_thompson5910(28593) About Me  on 2008-06-15 20:02:24 (Show Source):
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30%2Asqrt%2811%29-6%2Asqrt%2811%29 Start with the given expression


sqrt%2811%29%2830-6%29 Factor out the GCF sqrt%2811%29


sqrt%2811%29%2824%29 Subtract


24%2Asqrt%2811%29 Rearrange the terms


Expressions-with-variables/145410: Could someone tell me if I got this systems of equations problem right? This one is solved using the substitution method.
-3x + y = -4
x - y = 0
I got (2,2)
1 solutions

Answer 106083 by jim_thompson5910(28593) About Me  on 2008-06-15 19:42:35 (Show Source):
You can put this solution on YOUR website!

Start with the given system of equations:

system%28-3x%2By=-4%2Cx-y=0%29



Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to solve for y.




So let's isolate y in the first equation

-3x%2By=-4 Start with the first equation


y=-4%2B3x Add 3x to both sides


y=%2B3x-4 Rearrange the equation


---------------------

Since y=3x-4, we can now replace each y in the second equation with 3x-4 to solve for x



x-highlight%28%283x-4%29%29=0 Plug in y=3x-4 into the first equation. In other words, replace each y with 3x-4. Notice we've eliminated the y variables. So we now have a simple equation with one unknown.



x-3x%2B4=0 Distribute the negative


-2x%2B4=0 Combine like terms on the left side


-2x=0-4Subtract 4 from both sides


-2x=-4 Combine like terms on the right side


x=%28-4%29%2F%28-2%29 Divide both sides by -2 to isolate x



x=2 Divide





-----------------First Answer------------------------------


So the first part of our answer is: x=2









Since we know that x=2 we can plug it into the equation y=3x-4 (remember we previously solved for y in the first equation).



y=3x-4 Start with the equation where y was previously isolated.


y=3%282%29-4 Plug in x=2


y=6-4 Multiply


y=2 Combine like terms



-----------------Second Answer------------------------------


So the second part of our answer is: y=2









-----------------Summary------------------------------

So our answers are:

x=2 and y=2

which form the point








Now let's graph the two equations (if you need help with graphing, check out this solver)


From the graph, we can see that the two equations intersect at . This visually verifies our answer.




graph of -3x%2By=-4 (red) and x-y=0 (green) and the intersection of the lines (blue circle).


Radicals/145404: Perform the indicated operation.
-16√19+8√19
1 solutions

Answer 106080 by jim_thompson5910(28593) About Me  on 2008-06-15 19:10:12 (Show Source):
You can put this solution on YOUR website!
-16%2Asqrt%2819%29%2B8%2Asqrt%2819%29 Start with the given expression


sqrt%2819%29%28-16%2B8%29 Factor out the GCF sqrt%2819%29


sqrt%2819%29%28-8%29 Add


-8%2Asqrt%2819%29 Rearrange the terms


Quadratic_Equations/145405: Solve x%5E2-5x=11
1 solutions

Answer 106079 by jim_thompson5910(28593) About Me  on 2008-06-15 19:07:09 (Show Source):
You can put this solution on YOUR website!

x%5E2-5x=11 Start with the given equation.


x%5E2-5x-11=0 Get all terms to the left side.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=1, b=-5, and c=-11


Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%28-5%29+%2B-+sqrt%28+%28-5%29%5E2-4%281%29%28-11%29+%29%29%2F%282%281%29%29 Plug in a=1, b=-5, and c=-11


x+=+%285+%2B-+sqrt%28+%28-5%29%5E2-4%281%29%28-11%29+%29%29%2F%282%281%29%29 Negate -5 to get 5.


x+=+%285+%2B-+sqrt%28+25-4%281%29%28-11%29+%29%29%2F%282%281%29%29 Square -5 to get 25.


x+=+%285+%2B-+sqrt%28+25--44+%29%29%2F%282%281%29%29 Multiply 4%281%29%28-11%29 to get -44


x+=+%285+%2B-+sqrt%28+25%2B44+%29%29%2F%282%281%29%29 Rewrite sqrt%2825--44%29 as sqrt%2825%2B44%29


x+=+%285+%2B-+sqrt%28+69+%29%29%2F%282%281%29%29 Add 25 to 44 to get 69


x+=+%285+%2B-+sqrt%28+69+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%285%2Bsqrt%2869%29%29%2F%282%29 or x+=+%285-sqrt%2869%29%29%2F%282%29 Break up the expression.


So our answers are x+=+%285%2Bsqrt%2869%29%29%2F%282%29 or x+=+%285-sqrt%2869%29%29%2F%282%29


which approximate to x=6.653 or x=-1.653


Systems-of-equations/145402: y=1/2x-3 y=-2x-2
We need step by step explanation to solve thhis system of equations
1 solutions

Answer 106078 by jim_thompson5910(28593) About Me  on 2008-06-15 18:51:37 (Show Source):
You can put this solution on YOUR website!
y=%281%2F2%29x-3 Start with the first equation


-2x-2=%281%2F2%29x-3 Plug in y=-2x-2


%282%29%28-2x-2%29=%282%29%28%281%2Fcross%282%29%29x-3%29 Multiply both sides by the LCM of 2. This will eliminate the fractions (note: if you need help with finding the LCM, check out this solver)



-4x-4=x-6 Distribute and multiply the LCM to each side



-4x=x-6%2B4Add 4 to both sides


-4x-x=-6%2B4 Subtract x from both sides


-5x=-6%2B4 Combine like terms on the left side


-5x=-2 Combine like terms on the right side


x=%28-2%29%2F%28-5%29 Divide both sides by -5 to isolate x



x=2%2F5 Reduce. This is the first part of our answer.


y=%281%2F2%29x-3 Go back to the first equation


y=%281%2F2%29%282%2F5%29-3 Plug in x=2%2F5


y=1%2F5-3 Multiply


y=-14%2F5 Combine like terms



So our answer is x=2%2F5 and y=-14%2F5


Linear-systems/145401: Do you mind checking two more please?

1) -3x + y = -4
x - y = 0
I got y = 2, x = 2 (2,2)

2) 2x - y = -6
-2x + 2y = 4
I got y = -2, x = -4 (-2, -4)
1 solutions

Answer 106077 by jim_thompson5910(28593) About Me  on 2008-06-15 18:17:35 (Show Source):
You can put this solution on YOUR website!

# 1
Jump to problem #2





Start with the given system of equations:

system%28-3x%2By=-4%2Cx-y=0%29



Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to solve for y.




So let's isolate y in the first equation

-3x%2By=-4 Start with the first equation


y=-4%2B3x Add 3x to both sides


y=%2B3x-4 Rearrange the equation


y=%28%2B3x-4%29%2F%281%29 Divide both sides by 1


y=%28%28%2B3%29%2F%281%29%29x%2B%28-4%29%2F%281%29 Break up the fraction


y=3x-4 Reduce



---------------------

Since y=3x-4, we can now replace each y in the second equation with 3x-4 to solve for x



x-highlight%28%283x-4%29%29=0 Plug in y=3x-4 into the first equation. In other words, replace each y with 3x-4. Notice we've eliminated the y variables. So we now have a simple equation with one unknown.



x-3x%2B4=0 Distribute the negative


-2x%2B4=0 Combine like terms on the left side


-2x=0-4Subtract 4 from both sides


-2x=-4 Combine like terms on the right side


x=%28-4%29%2F%28-2%29 Divide both sides by -2 to isolate x



x=2 Divide





-----------------First Answer------------------------------


So the first part of our answer is: x=2









Since we know that x=2 we can plug it into the equation y=3x-4 (remember we previously solved for y in the first equation).



y=3x-4 Start with the equation where y was previously isolated.


y=3%282%29-4 Plug in x=2


y=6-4 Multiply


y=2 Combine like terms



-----------------Second Answer------------------------------


So the second part of our answer is: y=2









-----------------Summary------------------------------

So our answers are:

x=2 and y=2

which form the point








Now let's graph the two equations (if you need help with graphing, check out this solver)


From the graph, we can see that the two equations intersect at . This visually verifies our answer.




graph of -3x%2By=-4 (red) and x-y=0 (green) and the intersection of the lines (blue circle).














# 2
Jump to problem #1






Start with the given system of equations:

system%282x-y=-6%2C-2x%2B2y=4%29



Now in order to solve this system by using elimination/addition, we need to solve (or isolate) one variable. I'm going to solve for y.





In order to solve for one variable, we must eliminate the other variable. So if we wanted to solve for y, we would have to eliminate x (or vice versa).


So lets eliminate x. In order to do that, we need to have both x coefficients that are equal in magnitude but have opposite signs (for instance 2 and -2 are equal in magnitude but have opposite signs). This way they will add to zero. By adding to zero, they can be eliminated.



So to make the x coefficients equal in magnitude but opposite in sign, we need to multiply both x coefficients by some number to get them to an common number. So if we wanted to get 2 and -2 to some equal number, we could try to get them to the LCM.



Since the LCM of 2 and -2 is 2, we need to multiply both sides of the top equation by 1 and multiply both sides of the bottom equation by 1 like this:




1%282x-y%29=1%28-6%29 Multiply the top equation (both sides) by 1
1%28-2x%2B2y%29=1%284%29 Multiply the bottom equation (both sides) by 1




Distribute and multiply

2x-y=-6
-2x%2B2y=4


Now add the equations together. In order to add 2 equations, group like terms and combine them

%282x-2x%29%2B%28-y%2B2y%29=-6%2B4

Combine like terms and simplify



cross%282x-2x%29%2By=-2 Notice how the x terms cancel out




y=-2 Simplify



Now plug this answer into the top equation 2x-y=-6 to solve for x

2x-y=-6 Start with the first equation



2x-%28-2%29=-6 Plug in y=-2




2x%2B2=-6 Multiply



2x=-6-2Subtract 2 from both sides


2x=-8 Combine like terms on the right side


x=%28-8%29%2F%282%29 Divide both sides by 2 to isolate x



x=-4 Divide




So our answer is
x=-4 and y=-2



which also looks like




Now let's graph the two equations (if you need help with graphing, check out this solver)


From the graph, we can see that the two equations intersect at . This visually verifies our answer.




graph of 2x-y=-6 (red) and -2x%2B2y=4 (green) and the intersection of the lines (blue circle).