SOLUTION: 231=7(x+8)x

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Question 746091: 231=7(x+8)x
Answer by tommyt3rd(5050) About Me  (Show Source):
You can put this solution on YOUR website!
231=7(x+8)x
the 231 seems large, so we look for a way to simplify - and it turns out to be a multiple of 7:

7%2A33=7%2A%28x%2B8%29x

using cancellation and rearranging terms we get the following:
x%5E2%2B8x=33

x%5E2%2B8x-33=0

Notice that 11+(-3)=8 and (11)(-3)=-33 so we'll use them in our grouping:

x%5E3%2B11x-3x-33=0


x%28x%2B11%29-3%28x%2B11%29=0

%28x-3%29%28x%2B11%29=0

which has solutions

x=3 and x=-11

:)