SOLUTION: solve the equation by completeing the square x^2+2x=15

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Question 437260: solve the equation by completeing the square x^2+2x=15
Answer by Gogonati(855) About Me  (Show Source):
You can put this solution on YOUR website!
Add +1 on both sides of equation.
x%5E2%2B2x%2B1=15%2B1, complete the square on the left side.
%28x%2B1%29%5E2=16, by the square root definition we write: x+1=+/- sqrt(16)
x+1=4 => x=3 and x+1=-4 => x=-5.
Done.