SOLUTION: Let f(x)=x^2 +8x Solve f(x)=-16

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Question 1186777: Let f(x)=x^2 +8x
Solve f(x)=-16
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

f%28x%29=x%5E2+%2B8x
Solve f%28x%29=-16
-16=x%5E2+%2B8x
0=x%5E2+%2B8x%2B16.........write as a square of the sum
0=x%5E2+%2B8x%2B4%5E2
0=%28x%2B4%29%5E2
solution:
0=%28x%2B4%29=>x=-4