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Polynomials-and-rational-expressions/156948: Solve by factoring and using the principle of zero products.
18d^2 + 30d + 12 = 0

1 solutions

Answer 115708 by jim_thompson5910(28715) About Me  on 2008-09-14 19:36:24 (Show Source):
You can put this solution on YOUR website!

18d%5E2%2B30d%2B12=0 Start with the given equation


6%28d%2B1%29%283d%2B2%29=0 Factor the left side



Now set each factor equal to zero:


d%2B1=0 or 3d%2B2=0


d=-1 or d=-2%2F3 Now solve for d in each case


So our answers are


d=-1 or d=-2%2F3


Expressions-with-variables/156931: I have a problem 4a^2+18a+8/a+4 could you please work this out and show me
step by step how you did this Thanks
1 solutions

Answer 115702 by jim_thompson5910(28715) About Me  on 2008-09-14 19:01:32 (Show Source):
You can put this solution on YOUR website!

%284a%5E2%2B18a%2B8%29%2F%28a%2B4%29 Start with the given expression.


%282%28a%2B4%29%282a%2B1%29%29%2F%28a%2B4%29 Factor 4a%5E2%2B18a%2B8 to get 2%28a%2B4%29%282a%2B1%29.


%282highlight%28%28a%2B4%29%29%282a%2B1%29%29%2F%28highlight%28%28a%2B4%29%29%29 Highlight the common terms.


%282cross%28%28a%2B4%29%29%282a%2B1%29%29%2F%28cross%28%28a%2B4%29%29%29 Cancel out the common terms.


%282%282a%2B1%29%29%2F%281%29 Simplify.


2%282a%2B1%29 Reduce


4a%2B2 Distribute


So %284a%5E2%2B18a%2B8%29%2F%28a%2B4%29 simplifies to 4a%2B2.


In other words, %284a%5E2%2B18a%2B8%29%2F%28a%2B4%29=4a%2B2 where a%3C%3E-4.


Quadratic_Equations/156932: Evaluate the discriminate b^2-4ac. Then use the answer to state how many real number solutions exist for the rquation
y=x^2+8x+16
1 solutions

Answer 115700 by jim_thompson5910(28715) About Me  on 2008-09-14 18:55:36 (Show Source):
You can put this solution on YOUR website!

From x%5E2%2B8x%2B16 we can see that a=1, b=8, and c=16


D=b%5E2-4ac Start with the discriminant formula.


D=%288%29%5E2-4%281%29%2816%29 Plug in a=1, b=8, and c=16


D=64-4%281%29%2816%29 Square 8 to get 64


D=64-64 Multiply 4%281%29%2816%29 to get %284%29%2816%29=64


D=0 Subtract 64 from 64 to get 0


Since the discriminant is equal to zero, this means that there is one real solution.


Equations/156933: 45-3x=30
1 solutions

Answer 115699 by jim_thompson5910(28715) About Me  on 2008-09-14 18:54:26 (Show Source):
You can put this solution on YOUR website!

45-3x=30 Start with the given equation.


-3x=30-45 Subtract 45 from both sides.


-3x=-15 Combine like terms on the right side.


x=%28-15%29%2F%28-3%29 Divide both sides by -3 to isolate x.


x=5 Reduce.


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

Answer:

So the answer is x=5


Polynomials-and-rational-expressions/156935: Could someone please show me how to solve this equation? This is not coming up the way i need it to but the 7 is supposed to like a cubed square root. I am supposed to rewrite with rational exponents.
%28%287%29sqrt+%283x%5E2y%29%29%5E11
1 solutions

Answer 115698 by jim_thompson5910(28715) About Me  on 2008-09-14 18:52:52 (Show Source):
You can put this solution on YOUR website!
Remember,


So in this case,


Polynomials-and-rational-expressions/156872: Find the variation constant and an equation of variation where y varies directly as x and y=12 when x=3. The variation constant is k= ???
the equation of variation is y=???
1 solutions

Answer 115659 by jim_thompson5910(28715) About Me  on 2008-09-14 14:35:49 (Show Source):
You can put this solution on YOUR website!
The statement " y varies directly as x" translates to y=kx


y=kx Start with the given equation


12=k%283%29 Plug in y=12 and x=3


4=k Divide both sides by 3 to isolate "k"


So the variation constant is k=4 which means that the equation is y=4x


Polynomials-and-rational-expressions/156870: This question is from textbook college algebra
rule of signs to state the numbier of possible positive and negative real zeros of each polynomial function
P(x)=10x6 -9x5 -14x4 -8x3-18x2+x+6
I used my calculator to find the possible zeros and I understand there are 6 possible zeros
so far x=-1,-.6, .5, 2
1 solutions

Answer 115658 by jim_thompson5910(28715) About Me  on 2008-09-14 14:15:40 (Show Source):
You can put this solution on YOUR website!
Possible Zeros:


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 6 (the last coefficient):



Now let's list the factors of 10 (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




Number-Line/156865: How can I change an algebraic expression to the common languaje?
1 solutions

Answer 115656 by jim_thompson5910(28715) About Me  on 2008-09-14 13:44:58 (Show Source):
You can put this solution on YOUR website!
Post a problem so we can walk you through it


Distributive-associative-commutative-properties/156864: 10r-4(12+9r)
1 solutions

Answer 115655 by jim_thompson5910(28715) About Me  on 2008-09-14 13:44:10 (Show Source):
You can put this solution on YOUR website!

10r-4%2812%2B9r%29 Start with the given equation.


10r-48-36r Distribute.


-26r-48 Combine like terms



real-numbers/156862: The depth of a pool varies directly with how many gallons of water it will hold. If a 6 foot deep pool holds 10,000 gallons of water, a pool that holds 12,500 gallons of water should be __________inches deep, according to this theory. ??
1 solutions

Answer 115654 by jim_thompson5910(28715) About Me  on 2008-09-14 13:43:14 (Show Source):
You can put this solution on YOUR website!
We have the follow ratio:



number of gallons of pool # 1       number of gallons of pool # 2
---------------------------    =   -------------------------------
    depth of pool # 1                     depth of pool # 2






10000%2F6=12500%2Fx Plug in the given information


%2810000%2F6%29%2Ax=12500 Multiply both sides by x


10000%2Ax=12500%2A6 Multiply both sides by 6


10000%2Ax=75000 Multiply


x=75000%2F10000 Divide both sides by 10000


x=7.5 Divide


So a pool that is 7.5 feet deep will hold 12,500 gallons of water


Travel_Word_Problems/156861: This question is from textbook
Two runners leave the starting gate, one running 12mph and the other 10mph. If they maintain the pace, how long will it take for them to be 1/4 mile apart?
1 solutions

Answer 115652 by jim_thompson5910(28715) About Me  on 2008-09-14 13:31:17 (Show Source):
You can put this solution on YOUR website!
Let's set up the equation for the faster runner:


d=rt Start with the distance-rate-time formula


d=12t Plug in r=12


So after "t" hours, the faster runner has run 12t miles
----------------------------------

Let's set up the equation for the slower runner:


d=rt Start with the distance-rate-time formula


d=10t Plug in r=10

So after "t" hours, the faster runner has run 10t miles



Now if you want to know the distance between them, simply subtract the two expressions to get


12t-10t


Since we want the distance to be 1%2F4 of a mile, this means that

12t-10t=1%2F4




12t-10t=1%2F4 Start with the given equation.


4%2812t-10t%29=4%281%2Fcross%284%29%29 Multiply both sides by the LCD 4 to clear any fractions.


48t-40t=1 Distribute and multiply.


8t=1 Combine like terms on the left side.


t=%281%29%2F%288%29 Divide both sides by 8 to isolate t.


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

Answer:

So the answer is t=1%2F8 which approximates to t=0.125.


So in 1%2F8 of an hour (or 7 and half minutes) the distance between the two runners is 1%2F4 of a mile


Angles/156860: if angle a and angle b are complementary and angle b and angle c are supplementary how do they look?
1 solutions

Answer 115651 by jim_thompson5910(28715) About Me  on 2008-09-14 13:29:24 (Show Source):
You can put this solution on YOUR website!
If angle a and angle b are complementary, this means that they add to 90 degrees. This also means that they are both acute angles. Since angles b and c are supplementary, and we know that angle b is acute (ie less than 90 degrees), this means that angle c is obtuse


Here's one way you could draw the three angles


Photobucket - Video and Image Hosting


Exponential-and-logarithmic-functions/156859: This question is from textbook College Algebra
what is the simplest form of (x^-2y^-3)over (x^2y^-1)^3


1 solutions

Answer 115649 by jim_thompson5910(28715) About Me  on 2008-09-14 13:20:56 (Show Source):
You can put this solution on YOUR website!
%28x%5E%28-2%29y%5E%28-3%29%29%2F%28x%5E2y%5E%28-1%29%29%5E3 Start with the given expression


%28%281%2F%28x%5E%282%29%29%29%281%2F%28y%5E%283%29%29%29%29%2F%28x%5E2%281%2Fy%29%29%5E3 Rewrite x%5E%28-2%29 as 1%2F%28x%5E%282%29%29. Rewrite y%5E%28-3%29 as 1%2F%28y%5E%283%29%29. Rewrite y%5E%28-1%29 as 1%2F%28y%5E%281%29%29=1%2Fy


%28%281%29%2F%28x%5E2%2Ay%5E3%29%29%2F%28%28x%5E2%29%2F%28y%29%29%5E3 Combine the fractions


%28%281%29%2F%28x%5E2%2Ay%5E3%29%29%2F%28%28x%5E6%29%2F%28y%5E3%29%29 Distribute the outer exponent 3 to the inner exponents in the denominator


%28%281%29%2F%28x%5E2%2Ay%5E3%29%29%2A%28%28y%5E3%29%2F%28x%5E6%29%29 Multiply the first fraction by the reciprocal of the second fraction.


%28%281%29%2F%28x%5E%282%2B6%29%2Ay%5E3%29%29 Combine and multiply . Note: %28x%5E2%29%28x%5E6%29=x%5E%282%2B6%29


%28y%5E3%29%2F%28x%5E%288%29y%5E3%29 Add


%28y%5E%283-3%29%29%2F%28x%5E%288%29%29 Divide by subtracting the exponents.


%28y%5E%280%29%29%2F%28x%5E%288%29%29 Subtract


%281%29%2F%28x%5E%288%29%29 Simplify


So %28x%5E%28-2%29y%5E%28-3%29%29%2F%28x%5E2y%5E%28-1%29%29%5E3 simplifies to %281%29%2F%28x%5E%288%29%29


In other words, %28x%5E%28-2%29y%5E%28-3%29%29%2F%28x%5E2y%5E%28-1%29%29%5E3=%281%29%2F%28x%5E%288%29%29 where x%3C%3E0 or y%3C%3E0


Equations/156858: Please help me solve this: -5x + 3y = 7
1 solutions

Answer 115648 by jim_thompson5910(28715) About Me  on 2008-09-14 13:09:32 (Show Source):
You can put this solution on YOUR website!
Do you want to solve for "y"?



-5x%2B3y=7 Start with the given equation.


3y=7%2B5x Add 5x to both sides.


3y=5x%2B7 Rearrange the terms.


y=%285x%2B7%29%2F%283%29 Divide both sides by 3 to isolate y.


y=%285%2F3%29x%2B%287%29%2F%283%29 Break up the fraction.


So the solution is y=%285%2F3%29x%2B%287%29%2F%283%29


Geometry_Word_Problems/156845: if one leg of a triangle is 14 meters shorter than the other leg, and the hypotenuse is 26 meters, find the length of the two legs.

1 solutions

Answer 115647 by jim_thompson5910(28715) About Me  on 2008-09-14 13:09:14 (Show Source):
You can put this solution on YOUR website!

Leg 1: x


Leg 2: x%2B14 (since one leg is 14 m shorter than the other, the other leg is 14 m longer than the first one)


Hypotenuse: 26



a%5E2%2Bb%5E2=c%5E2 Start with Pythagorean's Theorem


x%5E2%2B%28x%2B14%29%5E2=26%5E2 Plug in the given information


x%5E2%2B%28x%2B14%29%5E2=676 Square 26


x%5E2%2Bx%5E2%2B28x%2B196=676 FOIL


2x%5E2%2B28x%2B196=676 Combine like terms


2x%5E2%2B28x%2B196-676=0 Subtract 676 from both sides.


2x%5E2%2B28x-480=0 Combine like terms.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=2, b=28, and c=-480


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-%2828%29+%2B-+sqrt%28+%2828%29%5E2-4%282%29%28-480%29+%29%29%2F%282%282%29%29 Plug in a=2, b=28, and c=-480


x+=+%28-28+%2B-+sqrt%28+784-4%282%29%28-480%29+%29%29%2F%282%282%29%29 Square 28 to get 784.


x+=+%28-28+%2B-+sqrt%28+784--3840+%29%29%2F%282%282%29%29 Multiply 4%282%29%28-480%29 to get -3840


x+=+%28-28+%2B-+sqrt%28+784%2B3840+%29%29%2F%282%282%29%29 Rewrite sqrt%28784--3840%29 as sqrt%28784%2B3840%29


x+=+%28-28+%2B-+sqrt%28+4624+%29%29%2F%282%282%29%29 Add 784 to 3840 to get 4624


x+=+%28-28+%2B-+sqrt%28+4624+%29%29%2F%284%29 Multiply 2 and 2 to get 4.


x+=+%28-28+%2B-+68%29%2F%284%29 Take the square root of 4624 to get 68.


x+=+%28-28+%2B+68%29%2F%284%29 or x+=+%28-28+-+68%29%2F%284%29 Break up the expression.


x+=+%2840%29%2F%284%29 or x+=++%28-96%29%2F%284%29 Combine like terms.


x+=+10 or x+=+-24 Simplify.


So the possible answers are x+=+10 or x+=+-24

However, a negative length isn't possible. So the only answer is x+=+10


So the first leg is 10 m, the second leg is 24 m (since 10%2B14=24), and the hypotenuse is 26 m



Exponential-and-logarithmic-functions/156857: 12^(m+5)=17
1 solutions

Answer 115643 by jim_thompson5910(28715) About Me  on 2008-09-14 12:53:05 (Show Source):
You can put this solution on YOUR website!
12%5E%28m%2B5%29=17 Start with the given equation


log%2810%2C%2812%5E%28m%2B5%29%29%29=log%2810%2C%2817%29%29 Take the log of both sides


%28m%2B5%29%2Alog%2810%2C%2812%29%29=log%2810%2C%2817%29%29 Rewrite the left side using the identity log%28b%2C%28x%5Ey%29%29=y%2Alog%28b%2C%28x%29%29


m%2B5=log%2810%2C%2817%29%29%2Flog%2810%2C%2812%29%29 Divide both sides by log%2810%2C%2812%29%29


m%2B5=log%2812%2C%2817%29%29 Use the change of base formula to rewrite the right side


m=log%2812%2C%2817%29%29-5 Subtract 5 from both sides


m=-3.85983 Use a calculator to evaluate the right side


So the exact answer is m=log%2812%2C%2817%29%29-5 which approximates to m=-3.85983


Equations/156856: Please help me solve this equation: 8x + 4y = 12
1 solutions

Answer 115642 by jim_thompson5910(28715) About Me  on 2008-09-14 12:45:57 (Show Source):
You can put this solution on YOUR website!
Do you want to solve for "y" ?



8x%2B4y=12 Start with the given equation.


4y=12-8x Subtract 8x from both sides.


4y=-8x%2B12 Rearrange the terms.


y=%28-8x%2B12%29%2F%284%29 Divide both sides by 4 to isolate y.


y=%28%28-8%29%2F%284%29%29x%2B%2812%29%2F%284%29 Break up the fraction.


y=-2x%2B3 Reduce.


Travel_Word_Problems/156854: a car is traveling at a speed of 55 miles per hour. you want to write an algebraic expression to show how far the car will travel in a certain number of hours. what will be your constant? your variable?
1 solutions

Answer 115641 by jim_thompson5910(28715) About Me  on 2008-09-14 12:43:18 (Show Source):
You can put this solution on YOUR website!
d=rt Start with the distance-rate-time formula


d=55t Plug in r=55


So in "t" hours, the car will travel 55t miles. For instance, if t=2, then 55t=55%282%29=110 which means in 2 hours the car travels 110 miles.


So the algebraic expression for the distance is 55t where 55 is the coefficient (in this case there is no constant) and t is the variable



Equations/156853: 6-2 x = -8
-
3
1 solutions

Answer 115639 by jim_thompson5910(28715) About Me  on 2008-09-14 12:38:18 (Show Source):
You can put this solution on YOUR website!

6-%282%2F3%29x=-8 Start with the given equation.


3%286-%282%2Fcross%283%29%29x%29=3%28-8%29 Multiply both sides by the LCD 3 to clear any fractions.


18-2x=-24 Distribute and multiply.


-2x=-24-18 Subtract 18 from both sides.


-2x=-42 Combine like terms on the right side.


x=%28-42%29%2F%28-2%29 Divide both sides by -2 to isolate x.


x=21 Reduce.


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

Answer:

So the answer is x=21


Exponents/156852: (3a^-2)^2(b^2c^3)^4/(ab)^-3 c^-4
1 solutions

Answer 115638 by jim_thompson5910(28715) About Me  on 2008-09-14 12:37:19 (Show Source):


Exponents/156851: K^4K^-5/(K^-2)^2
1 solutions

Answer 115636 by jim_thompson5910(28715) About Me  on 2008-09-14 12:30:49 (Show Source):


Triangles/156850: The hypotenuse of a right triangle is twice as long as one of the legs and 10 inches longer than the other. What are the lengths of the sides of the triangle?
So far I know that i should use the Pythagorean theorem.
I've drawn the triangle and know:
1st Leg: h/2
2nd Leg: h-10
Hypotenuse: h
(h-10)^2 + (h/2)^2 = h^2
4(h^2-20h-100+ (h^2/4))=h^2
4h^2-80h-400+h^2=h^2
5h^2-80h-400=h^2

1 solutions

Answer 115635 by jim_thompson5910(28715) About Me  on 2008-09-14 12:27:48 (Show Source):
You can put this solution on YOUR website!
You have the right equations set up, but your work is a little off.

%28h-10%29%5E2+%2B+%28h%2F2%29%5E2+=+h%5E2 Start with the given equation


h%5E2-20h%2B100+%2B+%28h%2F2%29%5E2+=+h%5E2 FOIL. Note: the third term is +100 (not -100)


h%5E2-20h%2B100+%2B+h%5E2%2F4+=+h%5E2 Square h%2F2 to get h%5E2%2F4


4h%5E2-80h%2B400+%2B+h%5E2+=+4h%5E2 Multiply EVERY term (including the terms on the right side) by the LCD 4 to eliminate the fraction



4h%5E2-80h%2B400%2Bh%5E2-4h%5E2=0 Subtract 4h%5E2 from both sides


h%5E2-80h%2B400=0 Combine like terms.


Notice we have a quadratic equation in the form of ah%5E2%2Bbh%2Bc where a=1, b=-80, and c=400


Let's use the quadratic formula to solve for h


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


h+=+%28-%28-80%29+%2B-+sqrt%28+%28-80%29%5E2-4%281%29%28400%29+%29%29%2F%282%281%29%29 Plug in a=1, b=-80, and c=400


h+=+%2880+%2B-+sqrt%28+%28-80%29%5E2-4%281%29%28400%29+%29%29%2F%282%281%29%29 Negate -80 to get 80.


h+=+%2880+%2B-+sqrt%28+6400-4%281%29%28400%29+%29%29%2F%282%281%29%29 Square -80 to get 6400.


h+=+%2880+%2B-+sqrt%28+6400-1600+%29%29%2F%282%281%29%29 Multiply 4%281%29%28400%29 to get 1600


h+=+%2880+%2B-+sqrt%28+4800+%29%29%2F%282%281%29%29 Subtract 1600 from 6400 to get 4800


h+=+%2880+%2B-+sqrt%28+4800+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


h+=+%2880+%2B-+40%2Asqrt%283%29%29%2F%282%29 Simplify the square root (note: If you need help with simplifying square roots, check out this solver)


h+=+%2880%29%2F%282%29+%2B-+%2840%2Asqrt%283%29%29%2F%282%29 Break up the fraction.


h+=+40+%2B-+20%2Asqrt%283%29 Reduce.


h+=+40%2B20%2Asqrt%283%29 or h+=+40-20%2Asqrt%283%29 Break up the expression.


h=74.641 or h=5.359 Now approximate the values of "h"


So the possible hypotenuses are h=74.641 or h=5.359


However, if you plug h=5.359 into h-10, you'll get a negative answer. So the only solution is h=74.641


So the length of the hypotenuse is approximately 74.641 units


So the first leg is 74.641%2F2=37.321 units long and the second leg is 74.641-10=64.641 units long


Equations/156849: This question is from textbook
Row 1 x = 10
Row 2 1/2 x = 10
Row 3 1/3x = 10
Row 100 1/100x = 10
Row n ? x = ?
As n gets larger, to what equation are the equations getting closer and closer? What is happening to the solutions?
1 solutions

Answer 115634 by jim_thompson5910(28715) About Me  on 2008-09-14 12:17:03 (Show Source):
You can put this solution on YOUR website!
I'm assuming that Row 2 is %281%2F2%29x. If that's the case, then Row n is %281%2Fn%29x. As "n" get's larger the value of 1%2Fn gets smaller and it approaches the value of zero. So the equations are getting closer and closer to zero as "n" increases.


Exponents/156848: (X^-1-X^-2)^-1
1 solutions

Answer 115632 by jim_thompson5910(28715) About Me  on 2008-09-14 12:07:58 (Show Source):


Radicals/156831: I need to find x, AB, and BC, where A, B, and C are points on a line...A is the leftmost point, C is the rightmost point, and B is in between A and C (not necessarily the midway)
AB = square root (3x +4)
BC = x-6
AC = 6
I was able to write out sqrt(3x+4) + x - 6 = 6, then simplifies to SQRT (3x+4) + x = 12. I don't understand how to eliminate the square root in these radical equations.
Please help.
Thank you.

1 solutions

Answer 115631 by jim_thompson5910(28715) About Me  on 2008-09-14 11:53:24 (Show Source):
You can put this solution on YOUR website!

sqrt%283x%2B4%29+%2B+x+-6=6 Start with the given equation.


sqrt%283x%2B4%29+%2B+x+=12 Add 6 to both sides.


sqrt%283x%2B4%29++=-x%2B12 Subtract "x" from both sides.


3x%2B4++=%28-x%2B12%29%5E2 Square both sides to eliminate the square root


3x%2B4++=x%5E2-24x%2B144 FOIL


0=x%5E2-24x%2B144-3x-4 Subtract 3x from both sides. Subtract 4 from both sides.


0=x%5E2-27x%2B140 Combine like terms.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=1, b=-27, and c=140


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-%28-27%29+%2B-+sqrt%28+%28-27%29%5E2-4%281%29%28140%29+%29%29%2F%282%281%29%29 Plug in a=1, b=-27, and c=140


x+=+%2827+%2B-+sqrt%28+%28-27%29%5E2-4%281%29%28140%29+%29%29%2F%282%281%29%29 Negate -27 to get 27.


x+=+%2827+%2B-+sqrt%28+729-4%281%29%28140%29+%29%29%2F%282%281%29%29 Square -27 to get 729.


x+=+%2827+%2B-+sqrt%28+729-560+%29%29%2F%282%281%29%29 Multiply 4%281%29%28140%29 to get 560


x+=+%2827+%2B-+sqrt%28+169+%29%29%2F%282%281%29%29 Subtract 560 from 729 to get 169


x+=+%2827+%2B-+sqrt%28+169+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%2827+%2B-+13%29%2F%282%29 Take the square root of 169 to get 13.


x+=+%2827+%2B+13%29%2F%282%29 or x+=+%2827+-+13%29%2F%282%29 Break up the expression.


x+=+%2840%29%2F%282%29 or x+=++%2814%29%2F%282%29 Combine like terms.


x+=+20 or x+=+7 Simplify.


So the possible answers are x+=+20 or x+=+7

However, if you plug x+=+20 back into the original equation, you'll find that it doesn't work.


So the only solution is x+=+7



Now plug in x+=+7 into AB, BC, and AC


AB=sqrt%283x%2B4%29=sqrt%283%287%29%2B4%29=sqrt%2821%2B4%29=sqrt%2825%29=5
BC=x-6=%287%29-6=1
AC=6


So the lengths are AB=5, BC=1, and AC=6

Check:

Remember, AB+BC=AC

AB+BC=AC ... Start with the given equation

5+1=6 ... Plug in AB=5, BC=1, and AC=6

6=6 ... Add Since this equation is true, this verifies the answer.


Radicals/156834: I need to resolve x, AB, BC and AC, where A, B and C are points on a line. A is leftmost, C is rightmost, and B is somewhere in between.
AB = 2x+1
BC = x-2
AC = sqrt (x^2 + 25x + 5)
Was able to write, 2x+1+x-2 = sqrt (x^2+25x+5), which reduces to 3x-1 = sqrt (x^2 + 25x + 5).
I don't know how to eliminate the square root, especially when there is an exponential along with it.
Please help.
Thank you.
1 solutions

Answer 115630 by jim_thompson5910(28715) About Me  on 2008-09-14 11:44:35 (Show Source):
You can put this solution on YOUR website!
I'll start where you left off

3x-1+=+sqrt+%28x%5E2+%2B+25x+%2B+5%29 Start with the given equation


%283x-1%29%5E2+=+x%5E2+%2B+25x+%2B+5 Square both sides. This will eliminate the square root.


9x%5E2-6x%2B1+=+x%5E2+%2B+25x+%2B+5 FOIL the left side


9x%5E2-6x%2B1-x%5E2-25x-5=0 Subtract x%5E2 from both sides. Subtract 25x from both sides. Subtract 5 from both sides.


8x%5E2-31x-4=0 Combine like terms.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=8, b=-31, and c=-4


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-%28-31%29+%2B-+sqrt%28+%28-31%29%5E2-4%288%29%28-4%29+%29%29%2F%282%288%29%29 Plug in a=8, b=-31, and c=-4


x+=+%2831+%2B-+sqrt%28+%28-31%29%5E2-4%288%29%28-4%29+%29%29%2F%282%288%29%29 Negate -31 to get 31.


x+=+%2831+%2B-+sqrt%28+961-4%288%29%28-4%29+%29%29%2F%282%288%29%29 Square -31 to get 961.


x+=+%2831+%2B-+sqrt%28+961--128+%29%29%2F%282%288%29%29 Multiply 4%288%29%28-4%29 to get -128


x+=+%2831+%2B-+sqrt%28+961%2B128+%29%29%2F%282%288%29%29 Rewrite sqrt%28961--128%29 as sqrt%28961%2B128%29


x+=+%2831+%2B-+sqrt%28+1089+%29%29%2F%282%288%29%29 Add 961 to 128 to get 1089


x+=+%2831+%2B-+sqrt%28+1089+%29%29%2F%2816%29 Multiply 2 and 8 to get 16.


x+=+%2831+%2B-+33%29%2F%2816%29 Take the square root of 1089 to get 33.


x+=+%2831+%2B+33%29%2F%2816%29 or x+=+%2831+-+33%29%2F%2816%29 Break up the expression.


x+=+%2864%29%2F%2816%29 or x+=++%28-2%29%2F%2816%29 Combine like terms.


x+=+4 or x+=+-1%2F8 Simplify.


So the possible answers are x+=+4 or x+=+-1%2F8

However, if you plug in x+=+-1%2F8 back into the original equation, you'll find that the equation won't be true. Also, since distance is ALWAYS positive, this means that x+=+-1%2F8 will not work (since if you plug it into any expression the result is negative)


So the only answer is x+=+4


Now plug in x=4 into AB,BC, and AC:

AB = 2x%2B1=2%284%29%2B1=8%2B1=9
BC = x-2=%284%29-2=2
AC =


So the three lengths are AB=9, BC=2, and AC=11

Check:

Remember, the segment addition postulate is AB+BC=AC (ie the lengths of the pieces of AC should add to the length of AC)

AB+BC=AC ... Start with the given equation

9+2=11 ...Plug in AB=9, BC=2, and AC=11

11=11 ... Add. Since this equation is true, this verifies the answer.


Radicals/156836: I need to resolve x, AB, BC and AC, where A, B and C are points on a line. A is leftmost, C is rightmost, and B is somewhere in between.
AB = 2x+1
BC = x-2
AC = sqrt (x^2 + 25x + 5)
Was able to write, 2x+1+x-2 = sqrt (x^2+25x+5), which reduces to 3x-1 = sqrt (x^2 + 25x + 5).
I don't know how to eliminate the square root, especially when there is an exponential along with it.
Please help.
Thank you.
1 solutions

Answer 115629 by jim_thompson5910(28715) About Me  on 2008-09-14 11:43:32 (Show Source):
You can put this solution on YOUR website!
I'll start where you left off

3x-1+=+sqrt+%28x%5E2+%2B+25x+%2B+5%29 Start with the given equation


%283x-1%29%5E2+=+x%5E2+%2B+25x+%2B+5 Square both sides. This will eliminate the square root.


9x%5E2-6x%2B1+=+x%5E2+%2B+25x+%2B+5 FOIL the left side


9x%5E2-6x%2B1-x%5E2-25x-5=0 Subtract x%5E2 from both sides. Subtract 25x from both sides. Subtract 5 from both sides.


8x%5E2-31x-4=0 Combine like terms.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=8, b=-31, and c=-4


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-%28-31%29+%2B-+sqrt%28+%28-31%29%5E2-4%288%29%28-4%29+%29%29%2F%282%288%29%29 Plug in a=8, b=-31, and c=-4


x+=+%2831+%2B-+sqrt%28+%28-31%29%5E2-4%288%29%28-4%29+%29%29%2F%282%288%29%29 Negate -31 to get 31.


x+=+%2831+%2B-+sqrt%28+961-4%288%29%28-4%29+%29%29%2F%282%288%29%29 Square -31 to get 961.


x+=+%2831+%2B-+sqrt%28+961--128+%29%29%2F%282%288%29%29 Multiply 4%288%29%28-4%29 to get -128


x+=+%2831+%2B-+sqrt%28+961%2B128+%29%29%2F%282%288%29%29 Rewrite sqrt%28961--128%29 as sqrt%28961%2B128%29


x+=+%2831+%2B-+sqrt%28+1089+%29%29%2F%282%288%29%29 Add 961 to 128 to get 1089


x+=+%2831+%2B-+sqrt%28+1089+%29%29%2F%2816%29 Multiply 2 and 8 to get 16.


x+=+%2831+%2B-+33%29%2F%2816%29 Take the square root of 1089 to get 33.


x+=+%2831+%2B+33%29%2F%2816%29 or x+=+%2831+-+33%29%2F%2816%29 Break up the expression.


x+=+%2864%29%2F%2816%29 or x+=++%28-2%29%2F%2816%29 Combine like terms.


x+=+4 or x+=+-1%2F8 Simplify.


So the possible answers are x+=+4 or x+=+-1%2F8

However, if you plug in x+=+-1%2F8 back into the original equation, you'll find that the equation won't be true. Also, since distance is ALWAYS positive, this means that x+=+-1%2F8 will not work (since if you plug it into any expression the result is negative)


So the only answer is x+=+4


Now plug in x=4 into AB,BC, and AC:

AB = 2x%2B1=2%284%29%2B1=8%2B1=9
BC = x-2=%284%29-2=2
AC =


So the three lengths are AB=9, BC=2, and AC=11

Check:

Remember, the segment addition postulate is AB+BC=AC (ie the lengths of the pieces of AC should add to the length of AC)

AB+BC=AC ... Start with the given equation

9+2=11 ...Plug in AB=9, BC=2, and AC=11

11=11 ... Add. Since this equation is true, this verifies the answer.


Quadratic_Equations/156773: Use the quadratic equation to solve
2x^2-5x=-9
Use i if complex answer.
i would appreciate a breakdown of the solution..Thanks
1 solutions

Answer 115592 by jim_thompson5910(28715) About Me  on 2008-09-13 23:10:21 (Show Source):
You can put this solution on YOUR website!

2x%5E2-5x=-9 Start with the given equation.


2x%5E2-5x%2B9=0 Add 9 to both sides.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=2, b=-5, and c=9


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%282%29%289%29+%29%29%2F%282%282%29%29 Plug in a=2, b=-5, and c=9


x+=+%285+%2B-+sqrt%28+%28-5%29%5E2-4%282%29%289%29+%29%29%2F%282%282%29%29 Negate -5 to get 5.


x+=+%285+%2B-+sqrt%28+25-4%282%29%289%29+%29%29%2F%282%282%29%29 Square -5 to get 25.


x+=+%285+%2B-+sqrt%28+25-72+%29%29%2F%282%282%29%29 Multiply 4%282%29%289%29 to get 72


x+=+%285+%2B-+sqrt%28+-47+%29%29%2F%282%282%29%29 Subtract 72 from 25 to get -47


x+=+%285+%2B-+sqrt%28+-47+%29%29%2F%284%29 Multiply 2 and 2 to get 4.


x+=+%285+%2B-+i%2Asqrt%2847%29%29%2F%284%29 Simplify the square root


x+=+%285%2Bi%2Asqrt%2847%29%29%2F%284%29 or x+=+%285-i%2Asqrt%2847%29%29%2F%284%29 Break up the expression.


So the answers are x+=+%285%2Bi%2Asqrt%2847%29%29%2F%284%29 or x+=+%285-i%2Asqrt%2847%29%29%2F%284%29


which approximate to x=1.25%2B1.714%2Ai or x=1.25%2B1.714%2Ai


Polynomials-and-rational-expressions/156767: Rewritethe following expression with positive exponents.
(5xy)^(-6/7)
I think its 1/ 5xy^7/6.... im probally wrong. Please help!
1 solutions

Answer 115585 by jim_thompson5910(28715) About Me  on 2008-09-13 22:22:14 (Show Source):
You can put this solution on YOUR website!
If m is negative, then x%5Em=1%2Fx%5Em. So in our case:



Quadratic_Equations/156738: write the equation of a quadratic f(x) such that f(0)=8 and a vertex at x=0.
1 solutions

Answer 115572 by jim_thompson5910(28715) About Me  on 2008-09-13 19:01:20 (Show Source):
You can put this solution on YOUR website!
Since the vertex is at x=0 and f%280%29=8 (which means that when x=0, then y=0), this means that the vertex is at the point (0,8). Now remember, the quadratic y=a%28x-h%29%5E2%2Bk has the vertex (h,k). So this means that in this case h=0 and k=8


y=a%28x-h%29%5E2%2Bk Start with the general quadratic in vertex form


y=a%28x-0%29%5E2%2B8 Plug in h=0 and k=8


y=ax%5E2%2B8 Subtract


So the quadratic equation which has the vertex at (0,8) is y=ax%5E2%2B8 where "a" can be any number. For example, y=2x%5E2%2B8 has the vertex at (0,8)


Exponential-and-logarithmic-functions/156731: equation y=ca^x
points on graph = (3,50) and (2,1)
Solve for a
1 solutions

Answer 115570 by jim_thompson5910(28715) About Me  on 2008-09-13 18:50:27 (Show Source):
You can put this solution on YOUR website!
y=ca%5Ex+ Start with the given equation


50=ca%5E3+ Plug in x=3 and y=50


50%2Fa%5E3=c+ Divide both sides by a%5E3 to isolate "c"


c=50%2Fa%5E3 Rearrange the equation


y=ca%5Ex+ Start with the given equation


1=ca%5E2+ Plug in x=2 and y=1


1=%2850%2Fa%5E3%29a%5E2+ Plug in c=50%2Fa%5E3


1=%2850a%5E2%29%2F%28a%5E3%29+ Multiply



1=50%2Fa+ Reduce


a=50+ Multiply both sides by "a"


So the solution is a=50+