Question

For this equation y=-2x^2+16x-24, Complete the square and reduce to the standard form: y-b=A(x-a)^2 ?

Answer 1

Isn't that general form, not standard form?
</nitpicking>

Answer 2

Completing the square, we see:
\[y=-2(x^2-8x+16)-24+32=-2(x-4)^2+8\implies y-8=-2(x-4)^2\]