Answer:
f(x)=-3(x+1)^2+27
Step-by-step explanation:
Forst, simplify the expression by pulling out -3, but leave 24 out.
=-3(x^2+2x)+24
Then complete the square of the equatio inside the parenthesis (remember to subtract from the outside what you add to the inside times -3).
=-3(x^2+2x+1)+24+3
=-3(x+1)^2+27
The equation is now in vertex form.
from that, we now know that the vertex is (-1,27).
Set this equation equal to 0 to find the x intercepts:
0=-3(x+1)^2+27
-27=-3(x+1)^2
9=(x+1)^2
3 and -3=x+1
x=2 and -4
