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vleith answered: 2822 problems
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Expressions-with-variables/210664: These are extra problems I need help to understand to bring up my grade please help I don't get it
Find the value for the given variable Show all steps and check answers showing all work. Not sure how to type in the problem.
a+1/6 = 2/a or a+1 over 6 = 2 over a
and
5/3x+1 = 3/3x-1 or 5 over 3x+1 = 3 over 3x-1










1 solutions

Answer 159162 by vleith(2825) About Me  on 2009-09-03 06:20:01 (Show Source):
You can put this solution on YOUR website!
%28a%2B1%29%2F6+=+2%2Fa+ multiply both sides by a to clear the denominator on the right
a%2A%28a%2B1%29%2F6+=+2 multiply both sides by 6 to clear the denominator on the left
a%2A%28a%2B1%29+=+12 expand the left side
a%5E2+%2B+a+=+12 subtract 12 from both sides
a%5E2+%2B+a+-+12+=+0 factor or use the quadratic equation. Here is a good URL to help check your factoring -->http://72.3.253.76:8080/webMathematica3/quickmath/page.jsp?s1=algebra&s2=factor&s3=basic
%28a%2B4%29%28a-3%29+=+0 in order for a product to be 0, one or more terms in the product must be 0. So in our case, either a%2B4+=0 or a-3=0
So solving those two equations, says either a=-4 or a=3 are solutions to the problem.
Substitute those values for a into the original equation to check your answers.

2)Use the same steps as above.
5%2F%283x%2B1%29+=+3%2F%283x-1%29 Clear right side denominator
%285%2A%283x-1%29%29%2F%283x%2B1%29+=+3 Clear left side denominator
5%2A%283x-1%29+=+3%2A%283x%2B1%29 this time, expand both sides
15x+-5+=+9x+%2B+3 collect like terms
15x+-+9x+=+3+%2B+5 simplfy
6x+=+8 divide both sides by 6
+x+=+8%2F6
x+=+4%2F3 simplify
Here is a great website for math. You can use it to verify your work. For this problem the URL is --> http://www.wolframalpha.com/input/?i=5%2F(3x%2B1)+%3D+3%2F(3x-1)


Polynomials-and-rational-expressions/210366: Hi I have three problem that I have to perform operation on and show my work.
-5x(3x^2-4x-9)
(5-3x)(4+7x)
(3x+5)^2
1 solutions

Answer 158978 by vleith(2825) About Me  on 2009-09-02 11:13:36 (Show Source):


Quadratic_Equations/210380: Use the quadratic formula to determine the x intercepts (if any) of the following function. Then evaluate the function for several values of x, and use the resulting points to graph the function. Show your work.
f(x)=7x^2-2
I have already come up with what I believe is the solution of the quadrtic,
x=0.534 x= -0.534.I don't understand how to get the other points on the graph and have it look like it's supposed to.
Thanks

1 solutions

Answer 158977 by vleith(2825) About Me  on 2009-09-02 11:10:02 (Show Source):
You can put this solution on YOUR website!
You have the correct x intercepts. Now you need to find the minimum point. You can see by looking at the function that the value x=0 will cause f(x) to be as small as it can get.
So calculate f(0)
f%280%29+=+7%2A0%5E2+-+2 = -2
Plot the points (0, -2), (0.534, 0) and (-0.534, 0)
Now draw a nice parabola thru them. If you need more points, just pick some x values (like 1 and -1), evaluate f(x) at those values for x and then plot those points too
graph%28400%2C400%2C+-5%2C5%2C-10%2C10%2C+7x%5E2-2%29


Coordinate-system/210385: without graphing, fing the minimum value
f(x)=3(x+12.68)^2-sqrt22
1 solutions

Answer 158974 by vleith(2825) About Me  on 2009-09-02 11:01:05 (Show Source):
You can put this solution on YOUR website!
Without graphing, to find the minimum value, you need to look at the terms and see which one(s) can change. You know that sqrt%2822%29 is a constant, so that one won't change. You can see that the first term 3%28x%2B12.68%29%5E2 involves a factor of that includes a square. You know that the minimum a squared value can be is 0 (A squared value is always going to be positive or 0).
So the minimum value occurs when the first term is 0.
So what value of x makes 3%28x%2B12.68%29%5E2=0
x+=+-12.68
When x = -12.68, then f%28x%29+=+0+-+sqrt%2822%29+=+-sqrt%2822%29


Percentage-and-ratio-word-problems/210362: what if at party, Leda Marie cut each buko pie into 2 serving pieces.If 63 halves pieces were eaten,how many pies were serve?
1 solutions

Answer 158968 by vleith(2825) About Me  on 2009-09-02 10:26:55 (Show Source):
You can put this solution on YOUR website!
Hard to say how many were served - we can say the minimum needed to make 63 peices.
We know that 63 halves were eaten, so 63/2 = 31.5 full pies.
She must have served at least 32 pies


Rectangles/210368: Find the maximum area of 45 the given perimeter of a rectangle. State the length and width of the rectangle.
1 solutions

Answer 158966 by vleith(2825) About Me  on 2009-09-02 10:23:47 (Show Source):
You can put this solution on YOUR website!
rule of thumb: the maximum area for a given rectangle perimeter is always a square. So in that case both the length and width are the same. Call it x
45+=+x%5E2
sqrt%2845%29+=+x


percentage/210375: Compute the requested value. Choose the correct answer.
If the selling price is $75.50 and includes the cost plus 5% of the cost, then what is the cost?
1 solutions

Answer 158963 by vleith(2825) About Me  on 2009-09-02 10:21:33 (Show Source):


Graphs/210378: Hi,
I'm having a little difficulty completing my project for algebra. Here's my question........
In a plotted graph, the x-axis represent weight and the y-axis represent miles. What would a slope of -13/22 mean?

Is it for every 13 miles decreasing the weight decreases by 22 pounds??????
1 solutions

Answer 158962 by vleith(2825) About Me  on 2009-09-02 10:20:04 (Show Source):
You can put this solution on YOUR website!
Close ... but not quite
For each decrease of 13 miles (-13), the weight increases by 22 (22)
graph%28400%2C+400%2C+-50%2C50%2C-50%2C50%2C+%28-13%2F22%29x%29


Linear_Algebra/210370: L=G m1m2/t^2 solve for m1
1 solutions

Answer 158961 by vleith(2825) About Me  on 2009-09-02 10:16:28 (Show Source):
You can put this solution on YOUR website!
L=G+%28m1%29%28m2%29%2Ft%5E2+ mutliply both sides by t%5E2
L+%2A+t%5E2+=+G%2A%28m1%29%2A%28m2%29 divide both sides by G%2A%28m2%29
%28L+%2A+t%5E2%29%2F%28G%2A%28m2%29%29+=+%28m1%29


Linear_Algebra/210374: 2x+y=8 solve for y
1 solutions

Answer 158960 by vleith(2825) About Me  on 2009-09-02 10:13:52 (Show Source):
You can put this solution on YOUR website!
2x%2By=8 solve for y by subtracting 2x from each side. This isolates y by itself on the left hand side
y+=+8+-+2x


Probability-and-statistics/210376: i can not figure this one out. can someone just tell me how to calculate.7 of 20,000. i get 14000 and that would only leave 6,000 which isnt an option. help please!!!
A contractor is considering a sale that promises a profit of $ 20,000 with a probability of .7 or a loss (due to bad weather, strikes, and such) of $ 3000 with a probability of .3. What is the expected profit?


A)

$ 16,100

B)

$ 17,000

C)

$ 13,100

D)

$ 14,000

1 solutions

Answer 158959 by vleith(2825) About Me  on 2009-09-02 10:12:15 (Show Source):
You can put this solution on YOUR website!
I think the question here is what does the contractor expect when a large enough set of similar deals happens.
You are told that contractor expects to make 20,000 70% of the time and lose 3000 30% of the time.
So what can the contractor expect if he/she does a bunch of these deals?
20000%2A0.7+-+3000%2A0.3
14000+-+900
13100


Numbers_Word_Problems/210342: in how many ways can 72 be expressed as product of two-digit Even numbers
1 solutions

Answer 158947 by vleith(2825) About Me  on 2009-09-02 06:21:27 (Show Source):
You can put this solution on YOUR website!
This is a really bad question.
I assume what they are really asking is "How many ways can 72 be expressed as a product of two-digit even Integers". That answer would be:
None.
For a quick check, use the smallest 2 digit even number --> 10
If 10 is used, the 'other number' would be 7.2.
Any even number larger than 10 would make the other number smaller than 7.2. Since 7.2 is NOT a two digit integer, then the answer is "none".
So what makes this a bad question?
The fact that the problem asked for two digit even 'numbers'. Since 10 and 7.2 both contain two digits, and are both even, then they work. Since there is going to be a "really big' number of similar two-digit (albeit non-integral) numbers, makes the answer to this one a mess.


Exponents/210343: 2/3 of a nunber decreased by 7=27.what is the number
1 solutions

Answer 158946 by vleith(2825) About Me  on 2009-09-02 06:14:37 (Show Source):
You can put this solution on YOUR website!
Let the number be represented by x. Using the info in the problem:
%282%2F3%29x+-+7+=+27
2x%2F3+=+34
2x+=+102
x+=+51


expressions/209966: can anyone solve this
3a+5(4a+6)=36
1 solutions

Answer 158672 by vleith(2825) About Me  on 2009-08-31 20:06:42 (Show Source):


Probability-and-statistics/209965: A bag contains 37 marbles. There are 10 red, 4 green, 9 yellow and the rest are blue. You reach into the bag, take out a marble, it is red. you set this marble in a bowl on the table and reach in the bag again. What is the probability that you will reach in and pull out a blue marble?
1 solutions

Answer 158670 by vleith(2825) About Me  on 2009-08-31 20:05:13 (Show Source):
You can put this solution on YOUR website!
first figure out how many blue marbles there are
BlueMarbles+=+TotalMarbles+-+Red+-+Green+-+Yellow
Blue+=+37+-+10+-+4-+9
Blue+=+14
After you draw one red marble, there are 36 marbles left in the bag.
So the probability of picking a blue marble = Blue%2FTotalInBag = 14%2F36 = 0.388


Graphs/209958: This question is from textbook Moving straight ahead Linear RelationShips
Im totaly lost on my 8th grade math homework. It says *For each equations in Exercises 18-21, give two values for x for which the value of y is negative.*
For 18. y=-2x-5
19. y= -4
20. y=2x-5
21. y=3/2x-1/4
1 solutions

Answer 158668 by vleith(2825) About Me  on 2009-08-31 20:01:35 (Show Source):
You can put this solution on YOUR website!
18) y=-2x-5
for y to be negative here, any x that is positive will do. Even x=0 would make y negative
y+=+-2%2A0+-+5
y+=+-5
You could solve it algebraically this way. In order for y to be negative, it must be "less than 0"
+0+%3E+-2x-5
5+%3E+-2x
-2.5+%3C+x so any x that is larger than -2.5 will give you a y that is negative. Look at the plot and you can see the same thing
graph%28400%2C400%2C+-10%2C10%2C-10%2C10%2C+-2x-5%29
19) y= -4
This is a horizontal line. So all x, no matter what value has a y = -4

20)
+y=2x-5
In this much like 18.
+0+%3E+2x+-+5
5+%3E+2x
2.5+%3E+x
Any x less than 2.5 yields a y that is negative
graph%28400%2C400%2C+-10%2C10%2C-10%2C10%2C+2x-5%29
21)
y=%283%2F2%29x-1%2F4
Same idea here
+0+%3E+%283%2F2%29x-1%2F4
1%2F4+%3E+%283%2F2%29x
2%2F12+%3E+x
1%2F6+%3E+x
Any x less than 1/6 works
graph%28400%2C400%2C+-10%2C10%2C-10%2C10%2C+%283%2F2%29x-1%2F4%29


expressions/209959: CAN ANYONE SOLVE THIS
3a+5(4a+6)
1 solutions

Answer 158663 by vleith(2825) About Me  on 2009-08-31 19:49:45 (Show Source):


Graphs/209800: Why does the equation y=(0.5)^x not have an x- intercept, using algebra?
1 solutions

Answer 158586 by vleith(2825) About Me  on 2009-08-31 06:15:31 (Show Source):
You can put this solution on YOUR website!
In order for a point to be an 'x-intercept', the y coordinate must be 0.
Let's substitute in y=0 and then attempt to solve for x
+y=%280.5%29%5Ex
Log%28y%29+=+x%2A+Log%280.5%29
Log%280%29+=+x%2ALog%280.5%29
The Log(0) is undefined, so y cannot be 0.
You can also try it another way
As x increases, the value of %280.5%29%5Ex approaches 0. However, 0 is the asymptote --> y never 'quite gets to 0, just really really close'


Miscellaneous_Word_Problems/207887: A rectangular deck has an area of (x2 + 6x + 8) square feet. If its width is (x + 2) feet then:
a. Find its length in terms of ‘x’.
b. If x = 3, what will be the area, length and width in feet.

1 solutions

Answer 157242 by vleith(2825) About Me  on 2009-08-22 07:44:21 (Show Source):
You can put this solution on YOUR website!
Area = (x^2 + 6x + 8)
Width = (x +2)
Area = Length * Width
Area/Width = Length
%28x%5E2+%2B+6x+%2B+8%29%2F%28x%2B2%29+=+Length
%28%28x%2B2%29%28x%2B4%29%29%2F%28x%2B2%29+=+Length
x%2B4+=+Length
If x=3 what are the area, length and width
Width = (x+2) = 3+2 = 5
Length = (x+4) = (3+4) = 7
Area = x^2 +6x + 8 = 3^2 + 6*3 + 8 = 9 + 18 + 8 = 35
Area = Length*Widht = 7 * 5 = 35


Miscellaneous_Word_Problems/207888: If a ball is thrown upwards at 40 feet per second from a rooftop 24 feet above the ground, then its height above the ground t seconds after it is thrown is given by h = - 16 t2 + 40 t + 24.
a. Rewrite the above formula with the polynomial on the right hand side factored completely.
b. Use the factored version of the formula to find h when t = 3.

1 solutions

Answer 157241 by vleith(2825) About Me  on 2009-08-22 07:40:26 (Show Source):
You can put this solution on YOUR website!
h+=+-+16+t%5E2+%2B+40+t+%2B+24
h+=+-8%2A%282t%5E2+-+5t+-+3%29
h+=+-8%2A%282t%2B1%29%28t-3%29
You can see that at t=3, the term (t-3) above would evaluate to 0.
Since 0* anything = 0, then h(3) = 0.


Graphs/207794: i posted these problems 4 days ago,but haven't received a response.could someone please help me.Thanks.
sketch the graphs,using the roots to find the function and the turning point
1.x = -8, x = 4
2.x = -3, x = 3
thanks for the help.hagd

1 solutions

Answer 157180 by vleith(2825) About Me  on 2009-08-21 15:19:23 (Show Source):
You can put this solution on YOUR website!
You are given roots, so you can figure out the quadratic. I will do the first one, you can use the same process to do the second one
1) roots are x=-8 and x=4
You know that at the roots, the value of the function is 0
You also know that for any product to equal zero, one or more terms in that function must be 0.
Thus
x =-8
x+8 = 0
x=
4
x-4=0
Now you have the two terms for your equation
%28x%2B8%29%28x-4%29+=+f%28x%29
x%5E2+-4x+%2B8x+-32+=+f%28x%29
x%5E2+%2B+4x+-+32+=+f%28x%29
This is the equation for the first problem. Since is it q quadratic, you know it is a parabola that opens up (opens up since the x^2 term is positive). You also know that the 'turning point' will be halfway between the two root. Since the roots are 12 units apart, the 'turning point' will be 6 units from each root.
-8+6 = -2
4-6 = -2
So find the value of f(x) when x=-2 and you'll have the minimum.
x%5E2+%2B+4x+-+32+=+f%28x%29
2%5E2+%2B4%2A2+-+32+=+f%282%29
4+%2B+8+-+32+=+f%282%29
-20+=+f%282%29
So the 'turning point is the point (2,-20)
Plot the funtion here --> http://www.wolframalpha.com/input/?i=x^2+%2B+4x+-+32+

Now do the same process for the other one. I am sure you can do it. If you still have questions, drop me an email


Graphs/207795: please help. I am trying to teach this to my daughter,but I need step by step instructions in order to do so .Thanks
solve for the unknown
1.5 = sqrt a + 2 (the 2 is not inside the sqrt symbol)
2.33 + 4 sqrt a = 6 sqrt a - 7 (7 is not inside the sqrt symbol)
thanks for the help. I really appreciate it.
1 solutions

Answer 157179 by vleith(2825) About Me  on 2009-08-21 15:09:08 (Show Source):
You can put this solution on YOUR website!
1)
5+=+sqrt%28a%29+%2B+2
5-2+=+sqrt%28a%29
3+=+sqrt%28a%29
3%5E2+=+%28sqrt%28a%29%29%5E2
9+=+a
2)
33+%2B+4%2Asqrt%28a%29+=+6%2Asqrt%28a%29+-+7
33%2B7+=++6%2Asqrt%28a%29+-++4%2Asqrt%28a%29
40+=+2%2Asqrt%28a%29
40%2F2+=+sqrt%28a%29
20+=+sqrt%28a%29
20%5E2+=++%28sqrt%28a%29%29%5E2
400+=+a
check your answers


test/207798: Please help me with this problem:
Write and solve an equation to find the value of x.
4.8, 1.6, 5.2, x; mean 3.7
Thanks!
1 solutions

Answer 157177 by vleith(2825) About Me  on 2009-08-21 15:03:13 (Show Source):
You can put this solution on YOUR website!
The mean is the average. There are 4 values to include in the calculation
%284.8+%2B+1.6+%2B+5.2+%2B+x%29%2F4+=+3.7
%2811.6%2Bx%29%2F4+=+3.7
11.6+%2B+x+=+3.7%2A4
11.6+%2B+x+=+14.8
x+=+14.8+-+11.6
x+=+3.2
Check your answer.


Polynomials-and-rational-expressions/207789: This question is from textbook Introductory Algebra
Please help me Preform the indicated operations and simplify:
%28x%5E2%29%2F%283x%5E2-5x-2%29-%282x%29%2F%283x%2B1%29*%281%29%2F%28x-2%29
1 solutions

Answer 157174 by vleith(2825) About Me  on 2009-08-21 14:42:35 (Show Source):


Miscellaneous_Word_Problems/207756: Turner agrees to buy a boat for $2,800 down and $129 a month for 48 months. What is the total cost of the boat?
1 solutions

Answer 157143 by vleith(2825) About Me  on 2009-08-21 09:00:16 (Show Source):


Miscellaneous_Word_Problems/207757: A stack of 1/2 plywood is 35 in. high. How many sheets of plywood are in the stack?
1 solutions

Answer 157142 by vleith(2825) About Me  on 2009-08-21 08:57:16 (Show Source):
You can put this solution on YOUR website!
Each sheet is 1/2 inch thick
StackHeight+=+1%2F2+%2A+NumberOfSheets
35+=+1%2F2+%2A+NumberOfSheets
70+=++NumberOfSheets


Problems-with-consecutive-odd-even-integers/207762: This question is from textbook algebra 1 an integrated approach
x/4+10>2
solve the problem

1 solutions

Answer 157141 by vleith(2825) About Me  on 2009-08-21 08:55:32 (Show Source):
You can put this solution on YOUR website!
x%2F4%2B10%3E2
x%2F4+%3E+-8
x+%3E+-32
plot is here --> http://www.wolframalpha.com/input/?i=x%2F4%2B10%3E2


absolute-value/207763: |n-(-4)|=6
n=___or___
1 solutions

Answer 157139 by vleith(2825) About Me  on 2009-08-21 08:53:54 (Show Source):
You can put this solution on YOUR website!
abs%28n+-+%28-4%29%29+=+6
So that means
n-+%28-4%29+=+6 or n+-+%28-4%29+=+-6
n%2B4+=+6 or n%2B4+=+-6
n+=+2 or n=-10


Volume/207749: Silver metal has a density of 10.5g/cm^3. A solid sphere of silver has mass of 0.295 g. What is the diameter of the silver piece, in mm? The volume of a sphere is V= (4/3)3.14*r^3 . I do not even know where to start with this.
1 solutions

Answer 157133 by vleith(2825) About Me  on 2009-08-21 04:52:20 (Show Source):
You can put this solution on YOUR website!
You are given the density of silver and told about a silver sphere that has a mass of 0.295g.
So you need to find the diameter of a sphere that with that mass.
First let's figure out what volume the sphere must be.
10.5g%2F%28cm%5E3%29+=+0.295g%2F%28VolumeofSphere%29
VolumeOfSphere+=+0.295%2F10.5+=+0.0280952%28cm%5E3%29
You are asked to find the sphere's diamter in mm. So let's convert the volume to (mm)^3
There are 10 mm/cm, so the converion from (mm)^3/(cm)^3 = 10*10*10 = 1000(mm)^3/(cm)^3
VolumeOfSphere+=+1000%2A.0280952+=+28.0952%28mm%29%5E3
You are ready ro solve
%284%2F3%29%2Api%2Ar%5E3+=+28.0952
r%5E3+=+%2828.0952%2A3%29%2F%284+%2A+pi%29
Now just grind out the value for r.
Once you have that, you need to remember you were asked for the diameter. So just double the radius and you are there.


Miscellaneous_Word_Problems/207607: A toy manufacturer produces model cars which are similar in every way to the actual cars. If the ratio of the door area of the model to the door area of the car is 1:2500, find
the ratio of the capacites of their petrol tanks
1 solutions

Answer 156995 by vleith(2825) About Me  on 2009-08-20 10:04:44 (Show Source):
You can put this solution on YOUR website!
First find the linear scale.
You are told two areas are scaled at 1:2500
You know area is measured in squared linear dimension.
SO, what is the sqaureroot of 2500?
sqrt%282500%29+=+50
Thus the linear scale is 1:50
Now, you are asked about 'capacity of the petrol tanks'. That is a volume. And volume are in cubic dimensions.
So the scale needs to be cubed
1%5E3%3A50%5E3
1%3A125000
wow


Coordinate-system/207611: 3x + 4y =12 graph the equation on the coordinate system
1 solutions

Answer 156993 by vleith(2825) About Me  on 2009-08-20 10:00:30 (Show Source):
You can put this solution on YOUR website!
The given equation is a line. So you need to find two points and then plot them.
For me, the easiest points to calculate are ones that have a 0 in one of the coordinates.
So let's find the point with where x=0
3x+%2B+4y+=12
3%2A0+%2B4y+=+12
y+=+12%2F4+=+3
So one point is (0,3)
Now find the point with a y coordinate of 0
3x+%2B+4y+=12
3x+%2B+4%2A0+=+12
x+=+12%2F3+=+4
Another point is (4,0)
Now, plot those two points (0,3) and (4,0).
Then draw the line that contains those two points.
See this URL for a plot --> http://www.wolframalpha.com/input/?i=3x+%2B+4y+%3D12