SOLUTION: Solve the equation by completing the square: x^2+12x-85=0

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Question 800921: Solve the equation by completing the square: x^2+12x-85=0
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
Given x%5E2%2B12x-85=0

Use the term, %2812%2F2%29%5E2=36 and add this to both sides of the equation.

x%5E2%2B12x-85%2B36=36
x%5E2%2B12x%2B36-85=36
x%5E2%2B12x%2B36-85%2B85=36%2B85
%28x%2B6%29%5E2=36%2B85
%28x%2B6%29%5E2=115
x%2B6=0%2B-+sqrt%28115%29, the zero included only to make rendering work on this site.
highlight%28x=-6%2B-+sqrt%28115%29%29