SOLUTION: What is the equation of the axis of symmetry of the function y=-2x^2-20x-47? I think the answer is x=-5 but I'm not sure. Can someone please explain?

Question 125323: What is the equation of the axis of symmetry of the function y=-2x^2-20x-47? I think the answer is x=-5 but I'm not sure. Can someone please explain?
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
To find the axis of symmetry, use this formula:

From the equation we can see that a=-2 and b=-20

Plug in b=-20 and a=-2

Negate -20 to get 20

Multiply 2 and -2 to get -4

Reduce

So the axis of symmetry is which means that you are correct.
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