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Earlsdon answered: 6281 problems
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Length-and-distance/375422: Hi
I asked for help before on this question and no one responded. I know its because its confusing. The problem is a trapazoid. The question is find volume in cubic feet. Here's my problem. The diagram only has one base(lower base) 25 feet. The shorter side is 9 feet and the longer side is 16 feet. and I think the three dimensional side to the right of the diagram is considered the depth? this is 18 feet. I know the formula for a trapezoid A=1/2 h (a+b)= but I'm not sure if I did 1/2 . 16.(25 + 9 )
1/2 . 16 .( 34 )
1/2. 544 = 270 is correct. Do you multiply that by 18
or is the whole problem WRONG because I"m not using a upperbase because I don't know what the upperbase is??? In the problem she gave us there are only four sets of numbers. 9 feet side, 16 feet side 25 feet base and 18 feet depth. It does not have a number for the upperbase. So I'm totally lost. Can anyone help please???? Thank You ever so much.
Janet
1 solutions

Answer 266996 by Earlsdon(6287) About Me  on 2010-11-23 13:01:15 (Show Source):
You can put this solution on YOUR website!
Janet, the best I can do with your description is the following:
It looks like you have a three-dimensional solid with one face in the shape of a trapezoid.
The trapezoid has dimensions of:
Base = 25ft.
Left side (perpedicular to the base) = 9ft.
Right side (perpendicular to the base) = 16ft.
Now extend this trapezoid shape 18ft. (We'll call this the "depth" of the solid) away from, but perpendicular to, the 25ft. base.
To find the volume of this solid, first find the area of the trapezoid.
A+=+%281%2F2%29%28b%5B1%5D%2Bb%5B2%5D%29%2Ah Substitute b%5B1%5D+=+9, b%5B2%5D+=+16, and h+=+25
A+=+%281%2F2%29%289%2B16%29%2825%29
A+=+%281%2F2%29%2825%29%2A%2825%29
A+=+%281%2F2%29%28625%29
A+=+312.5sq.ft.
Now find the volume by multiplying the area of the trapezoid (312.5sq.ft.) by the "depth" (18ft.).
V+=+%28312.5%29%2A%2818%29
highlight%28V+=+5625%29cu.ft.
I hope I have interpreted your description correctly.


Inverses/375122: My algebra teacher is having me retake a test on inderect and inverse variation. I have no clue how to do inderect and inverse variation. Can you help me find out?
1 solutions

Answer 266764 by Earlsdon(6287) About Me  on 2010-11-22 19:07:35 (Show Source):
You can put this solution on YOUR website!
First off, "indirect " variation and "inverse" variation mean exactly the same thing.
What is it.
When one quantity decreases as another quantity increases, the two quantities are said to vary inversely or indirectly.
Here's an example:
The air temperature goes down the higher you go.
So as the height increases, the temperature decreases.
We say that the air temperature varies inversely (indirectly) as the height.
You can write this algebraically as: (h = height and T = temperature)
T+=+k%2Fh The k is called the constant of variation and its value will depend upon the initial values of h and T that are provided in the problem.
For example, if you are told that the air temperature is 30 degrees farenheit at a height of 10,000 feet, you have enough information to find the value of k, the constant of variation.
T+=+k%2Fh Substitute T = 30 and h = 10,000
30+=+k%2F10000 Multiply both sides by 10,000
k+=+300000 so the equation now is:
T+=+300000%2Fh and this allows you to find the air temperature at any height, h.


test/375129: 10x³-51x²+54x
1 solutions

Answer 266760 by Earlsdon(6287) About Me  on 2010-11-22 18:40:27 (Show Source):
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10x%5E3-51x%5E2%2B54x First factor an x.
x%2810x%5E2-51x%2B54%29 Now factor the trinomial.
highlight%28x%285x-18%29%282x-3%29%29


Linear-equations/374310: An old house has a basement stairway that has steps with 7.25 inch risers and 9 inch treads. What is the slope of the stairway?
1 solutions

Answer 266377 by Earlsdon(6287) About Me  on 2010-11-21 10:41:48 (Show Source):
You can put this solution on YOUR website!
Remember; Slope = rise over run.
In this case, the rise is given as 7.25 inches and the run (also known as tread) is given as 9 inches.
So the slope is m+=+7.25%2F9=0.806


Distributive-associative-commutative-properties/374307: factor 3n + 9
1 solutions

Answer 266376 by Earlsdon(6287) About Me  on 2010-11-21 10:37:52 (Show Source):
You can put this solution on YOUR website!
Factor:
3n%2B9 Rewrite this as:
3n%2B3%2A3 Factor the 3 which is a common factor of both terms.
highlight%283%28n%2B3%29%29


Miscellaneous_Word_Problems/374317: I need some help understanding the steps for this question. Could someone help please?
Use the Pythagorean Theorem to solve the following:
The bottom of a 25 foot plank is placed approximately 7 feet from the side of a barn.
Approximately how far up the barn wall will the plank reach?

1 solutions

Answer 266375 by Earlsdon(6287) About Me  on 2010-11-21 10:30:43 (Show Source):
You can put this solution on YOUR website!
Notice that when you do as the problem instructs, you form a right triangle whose hypotenuse is the plank (25ft.) and whose base is the distance from the bottom of the plank to the side of the barn (7ft.).
The hypotenuse (labeled c) and the base (labeled b) can be used as b and c in the Pythagorean theorem. The height reached by the top of the plank will be repesented by a:
c%5E2+=+a%5E2%2Bb%5E2 Substitute c = 25 and b = 7.
25%5E2+=+a%5E2%2B7%5E2 Simplify.
625+=+a%5E2%2B49 Subtract 49 from both sides
576+=+a%5E2 Finally, take the square root of both sides.
24+=+a
The plank will reach exactly 24 feet up the barn wall.


Polynomials-and-rational-expressions/374311: I need to factor out this problem. I am missing a step. Can you explain how I factor?
5x^2+34x+24

1 solutions

Answer 266374 by Earlsdon(6287) About Me  on 2010-11-21 10:20:05 (Show Source):
You can put this solution on YOUR website!
How to factor:
5x%5E2%2B34x%2B24
To factor this trinomial, you need to find two binomials which, when multiplied, will give you the original trinomial.
In other words, find %28ax%2Bm%29 and %28bx%2Bn%29 such that %28ax%2Bm%29%28bx%2Bn%29+=+5x%5E2%2B34x%2B24
First, you look at the coefficient of x%5E2, and that's 5.
Now ask what are the factors of 5?
Well, 5 is a prime number, so the factors are 1 and 5.
So you can start with:
%285x%2Bm%29%28x%2Bn%29 Notice the a=5 and b+=+1
Now look at the constant term, that's 24.
You need to find the two integers, m and n, whose product is 24 and whose sum 5*n+1*m = 34.
Let's factor 24.
1X24 = 24
2X12 = 24
3X8 = 24
4X6 = 24
After a little trial & error, you'll find:
5*6+1*4 = 34
So this means that n = 6 and m = 4
Now you can finish by writing:
highlight%285x%5E2%2B34x%2B24+=+%285x%2B4%29%28x%2B6%29%29


Miscellaneous_Word_Problems/373985: The base of a triangle is 2 in.
longer than the height. The area is 12 in. to the second power . Find the
height and the base.
Could some one help please! Thank you!
1 solutions

Answer 266176 by Earlsdon(6287) About Me  on 2010-11-20 11:38:31 (Show Source):
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Given the base = height + 2 or:
b+=+h%2B2
And the area is 12 sq.in.
Start with the formula for the area of a triangle:
A+=+%281%2F2%29b%2Ah Substitute A+=+12 and b+=+h%2B2
12+=+%281%2F2%29%28h%2B2%29%2Ah Simplify by multiplying by 2.
2%2812%29+=+2%281%2F2%29%28h%2B2%29%2Ah Simplify.
24+=+%28h%2B2%29%2Ah or
24+=+h%5E2%2B2h Rearrange into standard quadratic equation form.
h%5E2%2B2h-24+=+0 Solve by factoring.
%28h-4%29%28h%2B6%29+=+0 Apply the zero product rule.
h-4+=+0 or h%2B6+=+0 which means that...
h+=+4 or h+=+-6 Discard the negative solution as height (h) is a positive quantity.
h+=+4
The height is 4 inches and the base is 6 (h+2)inches.


Quadratic_Equations/373986: Find all roots by factoring: f(x)=x^3+7x^2+10x
1 solutions

Answer 266174 by Earlsdon(6287) About Me  on 2010-11-20 11:24:15 (Show Source):
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Find all roots by factoring:
f%28x%29+=+x%5E3%2B7x%5E2%2B10x First, factor an x since this is a common factor in all three terms.
f%28x%29+=+x%28x%5E2%2B7x%2B10%29 Now factor the trinomial.
f%28x%29+=+x%28x%2B5%29%28x%2B2%29 Now set f%28x%29+=+0
x%28x%2B5%29%28x%2B2%29+=+0 Apply te zero product rule.
x+=+0 or x%2B5+=+0 or x%2B2+=+0 so the roots are:
x+=+0
x+=+-5
x+=+-2


Exponential-and-logarithmic-functions/373931: Solve the equation by making the bases the same on each side of the equation
5^x=1/125
1 solutions

Answer 266172 by Earlsdon(6287) About Me  on 2010-11-20 11:14:43 (Show Source):
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5%5Ex+=+1%2F125
5%5Ex+=+%28125%29%5E%28-1%29 Substitute 125+=+5%5E3
5%5Ex+=+%285%5E3%29%5E%28-1%29 Simplify.
5%5Ex+=+5%5E%28-3%29 The bases are equal, so the exponents are equal.
x+=+-3
Check:
5%5E%28-3%29+=+1%2F125
1%2F5%5E3+=+1%2F125 5%5E3+=+125 so...
1%2F125+=+1%2F125


Numbers_Word_Problems/373969: two-thirds of a number increased by 10, gives the same result as 25 subtracted from three times the number. find the number

1 solutions

Answer 266171 by Earlsdon(6287) About Me  on 2010-11-20 11:00:16 (Show Source):
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Let n be the number
%282%2F3%29n%2B10+=+3n-25 "Two-thirds of a number increased by 10, gives the same result as 25 subtracted from three times the number."
Multiply through by 3 to clear the fraction.
2n%2B30+=+9n-75 Subtract 2n from both sides.
30+=+7n-75 Add 75 to both sides.
105+=+7n Finally, divide both sides by 7.
15+=+n
The number is 15.


Exponential-and-logarithmic-functions/373938: The bases on each side of the equation cannot be made the same. Therefore, take the logarithm of each side in order to solve the equation.
log4 8
1 solutions

Answer 266168 by Earlsdon(6287) About Me  on 2010-11-20 10:52:17 (Show Source):
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Not quite sure what you are asking here!
Is it:
Log%5B4%5D%288%29+=+x ??? If so, then rewrite this in exponential form:
Log%5Bb%5D%28y%29+=+x--->b%5Ex+=+y so...
Log%5B4%5D%288%29+=+x--->4%5Ex+=+8 Now substitute 4+=+2%5E2 and 8+=+2%5E3 to get...
2%5E%282x%29+=+2%5E3 The bases are equal, so the exponents are equal, and...
2x+=+3 Divide both sides by 2.
x+=+3%2F2 so finally, we have...
Log%5B4%5D%288%29+=+3%2F2


Evaluation_Word_Problems/372543: if the square of a number is decreased by 15, the result is equal to the number increased by 15. what is the number?
1 solutions

Answer 265347 by Earlsdon(6287) About Me  on 2010-11-17 10:07:08 (Show Source):
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Let n = the number.
n%5E2-15+=+n%2B15 "...the square of a number (n) is decreased by 15, the result is equal to the number increased by 15."
Add 15 to both sides.
n%5E2+=+n%2B30 Subtract n from both sides.
n%5E2-n+=+30 Subtract 30 from both sides.
n%5E2-n-30+=+0 Solve this quadratic equation by factoring.
%28n%2B5%29%28n-6%29+=+0
n+=+-5 or n+=+6
As you can see, there are two answers:
-5 and 6


Graphs/370531: can you please graph the equation y=-2x+4 on a graph please?
1 solutions

Answer 264106 by Earlsdon(6287) About Me  on 2010-11-13 18:58:23 (Show Source):


Age_Word_Problems/370006: Mr. and Mrs. Wang are both 40 years old. They have a pair of twin daughters and a son. The product of the ages of the children is 36. Find the possible ages of the children.
1 solutions

Answer 263764 by Earlsdon(6287) About Me  on 2010-11-12 11:16:21 (Show Source):
You can put this solution on YOUR website!
Let's see what useful information we have!
The product of their ages is 36.
They have a pair of twin daughters.
Mr. & Mrs. Wang are 40 years old.
What are the possible ages of the children?
Let's first find the factors of 36 which will represent the possible ages of the three children:
1*1*36 = 36
1*2*18 = 36
1*3*12 = 36
1*4*9 = 36
1*6*6 = 36
2*2*9 = 36
3*3*4 = 36
Now select from this list the entries that have double (twin) integers.
1*1*36 = 36
1*6*6 = 36
2*2*9 = 36
3*3*4 = 36
The first entry doesn't qualify because if the parents are 40, they would not have a child who is 36.
This leaves the remaining entries:
1, 6, and 6.
2, 2, and 9.
3, 3, and 4.
as the possible ages.


Systems-of-equations/368770: I dont get how the whole solving system of equations by substitution and elimination thing works, so i need help with a few problems.
1 solutions

Answer 262823 by Earlsdon(6287) About Me  on 2010-11-09 23:19:33 (Show Source):
You can put this solution on YOUR website!
Please post your specific problems then a tutor can help you.


Graphs/367470: Find the equation of the line containing the given pair of points..
(-1,-5)(-4,-9)
1 solutions

Answer 261952 by Earlsdon(6287) About Me  on 2010-11-07 21:02:02 (Show Source):
You can put this solution on YOUR website!
You can start with the slope-intercept form: y+=+mx%2Bb
Find the slope:
m+=+%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 Substitute the x- and y-coordinates from the two given points: (-1,-5) and (-4,-9).
m+=+%28-9-%28-5%29%29%2F%28-4-%28-1%29%29 Evaluate.
m+=+%28-9%2B5%29%2F%28-4%2B1%29
m+=+%28-4%29%2F-3
m+=+4%2F3 So now you have:
y+=+%284%2F3%29x%2Bb Substitute the x- and y-coordinate values from any one of the tw given points and solve for b.
-5+=+%284%2F3%29%28-1%29%2Bb Evaluate.
-5+=+-4%2F3+%2B+b Add 4%2F3 to both sides.
-11%2F3+=+b The final eaquation is:
highlight%28y+=+%284%2F3%29x-11%2F3%29


Percentage-and-ratio-word-problems/367156: Where do I start?
OLD COINS: A salesperson used her $3,500 year-end bonus to purchase some old coins, with hopes of earning 15% annual interest on the gold coins and 12% annual interest on the silver coins. If she saw return on her investment of $480 the first year, how much did she invest in each type of coin?
1 solutions

Answer 261772 by Earlsdon(6287) About Me  on 2010-11-07 12:45:22 (Show Source):
You can put this solution on YOUR website!
You can start by assigning variables to the unknown quantities, the invested amounts in gold and in silver.
Let G = the number of dollars invested in gold and S = the number of dollars invested in silver.
The sum of these two amounts is given as $3,500.00, so you can write:
1) G%2BS+=+3500
Now we must find an equation for the amount of interest earned.
The interest earned on the gold investment is 15%(G) and the interest earned on the silver investment is 12%(S), and the sum of these two amounts is given as $480.00
So, after changing the percents to their decimal equivalents, you can write the equation:
2) 0.15G%2B0.12S+=+480
Now let's replace the G in equation 2) with its equivalent: G+=+3500-S which we get from equation 1) by solving for G.
3) 0.15%283500-S%29%2B0.12S+=+480 Simplify and solve for S.
3a) 525-0.15S%2B0.12S+=+480
3b) 525-0.03S+=+480 Subtract 525 from both sides.
3c) -0.03S+=+-+45 Finally, divide both sides by -0.03
3d) highlight%28S+=+1500%29 This is the number of dollars invested in silver.
G+=+3500-S
G+=+3500-1500
highlight_green%28G+=+2000%29 and this is the number of dollars invested in gold.


Equations/367163: If Kevin can do a job in five hours and Carrie can do the same job in 4 hours how long will it take for them to do the job together? Could you please explain your answer as well
1 solutions

Answer 261765 by Earlsdon(6287) About Me  on 2010-11-07 12:20:08 (Show Source):
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Find the hourly rate of each person.
If Kevin can do the job in 5 hours, then he can do 1%2F5 of the job in 1 hour.
If Carrie can do the job in 4 hours, then she can do 1%2F4 of the job in 1 hour.
So together, they can do 1%2F5%2B1%2F4+=+9%2F20 of the job in 1 hour.
This means that it will take them 20%2F9+=+22%2F9 hours to complete the job together.
22%2F9hours = 2hours,13minutes and 20seconds.


Linear-equations/366334: "The line is perpendicular to y=2x-4 and passes though (4,7)"
Could you plese show me the formula on how to get the answer in y=mx+b form?
1 solutions

Answer 261065 by Earlsdon(6287) About Me  on 2010-11-04 21:50:17 (Show Source):
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I don't know that I can show you a "formula" but I can show you a procedure.
You want your answer to be an equation in the slope-intercept form:
y+=+mx%2Bb of a line that is perpendicular to the line y+=+2x-4 and which passes through the point (4, 7).
Let's start with the slope:
If two lines are perpendicular, their slopes are the negative reciprocal of each other.
The given line is: highlight%28y+=+2x-4%29. Since this is in the slope-intercept form: y+=+mx%2Bb you can see that the slope m+=+2.
The negative reciprocal of 2 is -1%2F2.
So you can start with:
y+=+%28-1%2F2%29x%2Bb but now you need to find the value of b, the y-intercept.
So we substitute the x- and y-coordinate values of the given point (4, 7) into the equation above and solve for b.
7+=+%28-1%2F2%29%284%29%2Bb Simplify this:
7+=+-2%2Bb Add 2 to both sides.
9+=+b Now that we have the value of b, we can write the final equation.
highlight_green%28y+=+%28-1%2F2%29x%2B9%29
And just to show you what these look like when graphed:
graph%28400%2C400%2C-5%2C20%2C-5%2C20%2C2x-4%2C%28-1%2F2%29x%2B9%29


Exponential-and-logarithmic-functions/366340: write with no denominators:
ax^2/b^3y
1 solutions

Answer 261056 by Earlsdon(6287) About Me  on 2010-11-04 21:29:03 (Show Source):
You can put this solution on YOUR website!
Write with no denominators:
ax%5E2%2Fb%5E3y+=+ax%5E2b%5E%28-3%29y%5E%28-1%29


Mixture_Word_Problems/366163: how many quarts of pure antifreeze must be added to 6 quarts of a 10% antifreeze solution to obtain a 30%antifreeze solution?
1 solutions

Answer 260935 by Earlsdon(6287) About Me  on 2010-11-04 16:09:06 (Show Source):
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First, think in terms of the amounts of antifreeze in this situation.
Let x = the number of quarts of pure antifreeze to be added.
How much antifreeze is there in the six quarts of 10% antifreeze solution?
6quarts(10%) = 0.6 quarts of antifreeze.
The final antifreeze solution will be 6+x quarts of 30% antifreeze.
So now we can write the necessary equation to solve for x.
x+0.1(6) = 0.3(x+6) Simplify and solve for x.
x+0.6 = 0.3x+1.8 Subtract 0.3x from both sides.
0.7x+0.6 = 1.8 Subtract 0.6 from both sides.
0.7x = 1.2 Finally, divide both sides by 0.7
x = 1.71429
So you'll need to add 1.71429 quarts of pure antifreeze to the 6 quarts of 10% antifreeze solution to obtain 7.71429 (6+1.71429) quarts of 30% antifreze solution.


Linear_Equations_And_Systems_Word_Problems/365352: a tree that is 2 feet tall is growing at a rate of 1 foot per year.A 6 foot tall tree is growing at a rate of 0.5 foot per year. in how many years will the trees be the same heigth
1 solutions

Answer 260443 by Earlsdon(6287) About Me  on 2010-11-02 21:32:08 (Show Source):
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Let x = the number of years when the two trees will be the same height.
For the 2ft tree, you can express its height in x years as:
2+1(x)
And for the 6ft. tree...
6+0.5(x)
So you need to find the value of x that would make these equal.
2+x = 6+0.5x Subtract 0.5x from both sides.
2+0.5x = 6 Now subtract 2 from both sides.
0.5x = 4 Finally, divide both sides by 0.5
x = 8
So in 8 years, the two trees will be the same height.


Miscellaneous_Word_Problems/364182: The height of a falling object dropped form a height of 100m is described by h=100-16t2 where t is time measured in seconds.
Find i) The velocity at t = 2
ii) The acceleration at t = 2

1 solutions

Answer 259722 by Earlsdon(6287) About Me  on 2010-10-31 15:13:51 (Show Source):
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The height (as a function of time, t) of an object falling from 100 meters is described by:
h%28t%29+=+100-16t%5E2
i) Find the velocity at t = 2
The velocity is the rate of change of distance with respect to time, t.
If we take the first derivative of the height fuction, we will get the eqation for the velocity.
dh%2Fdt+=+-32t and at t=2, we get:
dh%2Fdt+=+-32%282%29 dh%2Fdt+=+v
v+=+-64meters/second. The negative indicates a downward direction.
ii) Find the acceleration at t = 2.
Acceleration, which is the rate of change of velocity with respect to time, t, can be found by taking the second derivative of the height function (h%28t%29+=+100-16t%5E2):
d%5E2t%2Fdt%5E2+=+d%28dh%2Fdt%29%2Fdt=d%28-32t%29%2Fdt+=+-32meters/second squared.
d%5E2t%2Fdt%5E2+=+a
a+=+-32meters/second squared. A constant.


Quadratic_Equations/364165: write a quadratic equation in the variable x having given numbers as solutions. Type in standard form solution 9, only solution?
1 solutions

Answer 259713 by Earlsdon(6287) About Me  on 2010-10-31 13:35:08 (Show Source):
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The solution(s) to a quadratic equation is(are) x = 9.
Yes, a quadratic equation may have a "single" solution, but this is known as a "double" solution.
To write the equation whose solution(s) is(are) x = 9, you will start by setting x = 9.
To get such a solution you must have found the factors of the quadratic equation to be:
x-9+=+0 and x-9+=+0 Now if you multiply these factors together, the result will be the generating quadratic equation:
%28x-9%29%28x-9%29+=+x%5E2-18x%2B81
So the equation is:
highlight%28y+=+x%5E2-18x%2B81%29
Here's the graph of this quadratic equation and you can see why there appears to be a "single" solution:
graph%28400%2C400%2C-5%2C20%2C-5%2C100%2Cx%5E2-18x%2B81%29


Functions/364145: I know that this is algebra and x is the argument what does that mean this problem Please help me understand and solve this equation -5+X=20
Imani Robinson
Kipp Stand Academy
6th grade
1 solutions

Answer 259712 by Earlsdon(6287) About Me  on 2010-10-31 13:21:27 (Show Source):
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Solve -5%2Bx+=+20
When you are asked to solve a problem such as this, you are being asked to find the value of x that, when added to -5 will give the result of 20.
You can solve this equation for x this way:
-5%2Bx+=+20 To isolate the variable, x, you must add 5 to both sides of the equation. When you do this, you are "undoing" the -5 so that you are left with the variable by itself on the left side of the equation.
-5%2B5%2Bx+=+20%2B5 Because -5%2B5+=+0, we are left with x by itself on the left side:
x+=+20%2B5 ...and on the right side, you can see that 20%2B5+=+25 so...
highlight%28x+=+25%29
To see if this is really the correct solution for x, we'll substitute x+=+25 into the original equation to see if both sides are equal.
-5%2Bx+=+20 Substitute x+=+25%7D%0D%0A%7B%7B%7B-5%2B25+=+20 and, since -5%2B25+=+20 or 25-5+=+20 we have:
20+=+20


Polynomials-and-rational-expressions/364152: factor the polynomial completely
3x^2 + 8x + 4



1 solutions

Answer 259711 by Earlsdon(6287) About Me  on 2010-10-31 13:07:59 (Show Source):
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Factor:
3x%5E2%2B8x%2B4
The first term has the factors: highlight%28%283x%29%28x%29%29
The last term has the factors: %281%29%284%29 or highlight_green%28%282%29%282%29%29
Since the middle term is: 8x we can get this by %283x%29%282%29%2B%28x%29%282%29, so...
3x%5E2%2B8x%2B4+=+%283x%2B2%29%28x%2B2%29


Exponents-negative-and-fractional/364151: multiply and simplify
(10y - 1/4)(5y - 1/2)
This is what I have
50y^2 - 5 - 5/4 + 1/8
50y^2 - 5 - 11/8
This is as far as I got





1 solutions

Answer 259710 by Earlsdon(6287) About Me  on 2010-10-31 13:01:01 (Show Source):
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Multiply & simplify:
%2810y-1%2F4%29%285y-1%2F2%29 Using FOIL, we get:
50y%5E2-5y-%285%2F4%29y%2B1%2F8 Simplifying gives us:
50y%5E2-%2825%2F4%29y%2B1%2F8 or
50y%5E2-6%281%2F4%29y%2B1%2F8


Linear_Equations_And_Systems_Word_Problems/357390: A baseball is hit straight upwards with an initial velocity of 76 feet per second and leaves the bat at an initial height of 2 feet. Write a formula, s(t), that models the height of the baseball after t seconds.

1 solutions

Answer 255228 by Earlsdon(6287) About Me  on 2010-10-17 13:05:40 (Show Source):
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You could start with the general formula for the height of an object (s) as a function of time (t), s(t), propelled upwards with an initial velocity (v%5B0%5D) from an initial height (h%5B0%5D):
s%28t%29+=+%281%2F2%29gt%5E2%2Bv%5B0%5Dt%2Bh%5B0%5D where g (constant of acceleration due to gravity) = -32 ft/sec^2. So substitute g = 32, v%5B0%5D+=+76, and h%5B0%5D+=+2
highlight%28s%28t%29+=+-16t%5E2%2B76t%2B2%29
Note: The acceleration due to gravity is negative because it is in a downward direction.


Polynomials-and-rational-expressions/357380: A customer wants to make a teepee in his backyard for his children. He plans to use lengths of PVC plumbing pipe for the supports on the teepee, and he wants the teepee to be 6 feet across and 4 feet tall (see figure). How long should the PVC plumbing pipe be?
I tried to copy and paste the figure but I'm not sure if you can see it or not.
1 solutions

Answer 255225 by Earlsdon(6287) About Me  on 2010-10-17 12:40:26 (Show Source):
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If you look at the tepee from the side you will see an isoceles triangle whose height is 4 feet and whose base is 6 feet.
If you drop a line from the apex perpendicular to the base you will have two right triangles. The height of the right triangle is 4 feet and the base will be just half of the width of the base of the isoceles triangle, or 3 feet.
You need to find the length of the hypotenuse of the right triangle.
Use:
c%5E2+=+a%5E2%2Bb%5E2 Substitute a = 3 and b = 4
c%5E2+=+9%2B16
c%5E2+=+25 Take the square root of both sides.
c+=+5
The PVC plumbing pipe should be 5 feet long.


Surface-area/357369: A regular hexagon has an apothem of 7root3 cm. What is the area of this hexagon?
1 solutions

Answer 255221 by Earlsdon(6287) About Me  on 2010-10-17 12:31:25 (Show Source):
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The area of a regular polygon can be expressed in terms of its apothem (r) (the perpendicular distance from the center to a side of the polygon) and the number (n) of sides in the polygon.
A regular hexagon has 6 sides so n = 6 and the apothem (r) is given as 7%2Asqrt%283%29
A+=+nr%5E2tan%28180%2Fn%29 Substitute n = 6 and r+=+7%2Asqrt%283%29:
A+=+6%2A%287%2Asqrt%283%29%29%5E2tan%28180%2F6%29 Evaluate.
A+=+6%28147%29tan30
A+=+882%2A0.577
A+=+509sq.cm.