((4-2x)/(x+2)) = x-2
(4-2x)/(x+2) = x-2
4-2x = (x-2)(x+2)
4-2x = x²-4
x²+2x-8=0
(x+4)(x-2) = 0
x+4=0
x=-4
x-2=0
x=2
2007-03-11 18:14:04
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answer #1
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answered by datz 2
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Problem:
4 - 2X
-------- = X - 2
X + 2
1) Cross Multiply.
4 - 2X * 1
Since there is no denominator under X-2, the denominator is automatically 1
(X-2) * (X+2)
When you multiply 4 - 2X * 1 you get 4 - 2X.
When you multiply (X - 2)(X+2) you must foil.
The result is:
x^2 -4
2) Set the two resulting answers equal to one another.
X^2 - 4 = 4 - 2X
3) Normally I would say move all X's to one side of the equation. However, since we have an X^2, I can see we ought to move everything over to one side and set it equal to 0.
Thus, I will move -2X and 4 to the left side of the equation by adding 2X to both sides and subtracting 4 from both sides, as these two moves cause the numbers to cancel on the right. The result is as follows:
X^2 + 2X -8 = 0
4) Factor:
(X + 4) (X - 2) = 0
5) Set each factor equal to 0 and solve:
X + 4 = 0
X = -4
X - 2 = 0
X = 2
6) Your answers are that X = 2 and -4. Going back to the original equation we try the answers to see if they are correct.
You will see that both solutions work.
2007-03-11 18:49:43
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answer #2
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answered by Anonymous
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4-2x ............ x-2
---------...=
x+2
cross multiply
4 - 2x = (x+2)(x-2)
4 - 2x = x^2 - 4
subtract 4 - 2x from both sides
0 = x^2 - 4 - 4 + 2x
0 = x^2 + 2x - 8
rewrite it with the zero on the right side
x^2 + 2x - 8 = 0
factor it out
(x+4)(x-2) = 0
x+4 = 0; x = -4
x-2 = 0; x = 2
then you have to make sure both of those answers dont give you a zero denominator (x+2 cannot equal zero)
2+2=4: -4+2=2
these are both nonzero so we are fine
answer; x=2, x = -4
2007-03-11 20:43:55
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answer #3
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answered by Bill F 6
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I think the answer should be x^2 + 2x - 8 or (x+4)(x-2)
(the x^2 is x squared)
2007-03-11 18:31:17
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answer #4
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answered by Gail C 2
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4-2x = x^2-4
0=x^2+2x-8
=(x+4)(x-2)
x=-4 or x =2
2007-03-11 18:47:47
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answer #5
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answered by Anonymous
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(4-2x) = (x-2)(x+2)
(4-2x)=x^2-4
x^2+2x-8=0
x=2 or -4
2007-03-11 18:14:28
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answer #6
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answered by KingSAT 2
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((4-2x)/(x+2)) = x-2
(-2*(x-2)/(x+2))=x-2
x+2=-2 (divide out (x-2) on each side)
x=-4
2007-03-11 18:12:38
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answer #7
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answered by tobysamples 1
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