SOLUTION: find the line of symmetry f(x)=-(x+4)^2+9

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Question 266385: find the line of symmetry f(x)=-(x+4)^2+9
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
f(x)=-(x+4)^2+9
f(x)=-(x^2+8x+16)+9
f(x)=-x^2-8x-16+9
f(x)=-x^2-8x-7 complete the square.
x^2+8x+16=-7+16
(x+4)^2=9
x+4=0
x=-4
Axis of symetry is x=-4
+graph%28+300%2C+200%2C+-6%2C+5%2C+-10%2C+10%2C+-x%5E2+-8x+-7%29+ (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, -x^2 -8x -7).