<PRE><B>Question 973237</B>
Multiply the whole equation by x^2+4x-21, written as (x-3)(x+7) as you have.

The first term  has the x+7 cancel
it is 5(x-3).  The second term has the x-3 cancel and is 4(x+7).  The answer is now x-11

Distribute, and you have  5x-15  + 4x +28=x-11
9x+13=x-11
8x=-24
x= -3

(5/4) -(4/6) = -14/24


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