SOLUTION: Simplify (2x-7)^2-(x+5)^2

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Question 166167: Simplify (2x-7)^2-(x+5)^2
Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!
%282x-7%29%5E2-%28x%2B5%29%5E2 , Original eqn
expand:
4x%5E2-28x-49-%28x%5E2%2B10x%2B25%29
4x%5E2-28x%2B49-x%5E2-10x-25
3x%5E2-38x%2B24 ---> This is simplified form
Solving for "x", by Pyth.Theorem
Given --- system%28a=3%2Cb=-38%2Cc=24%29
x%5E2=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29
Plug in the values, you'll arrive for "x" --system%28x=12%2Cx=2%2F3%29
Check via Original eqn:
%282%2812%29-7%29%5E2-%2812%2B5%29%5E2
%2824-7%29%5E2-%2817%29%5E2
%2817%29%5E2-289
289-289=0
Also,
%282%282%2F3%29-7%29%5E2-%282%2F3%2B5%29%5E2
%28%284%2F3%29-7%29%5E2-%2817%2F3%29%5E2
%28-17%2F3%29%5E2-%2817%2F3%29%5E2=0
Thank you,
Jojo