Answer:
3999
Step-by-step explanation:
D)
f(x) = x^2 -14x -72
0=x^2 - 14x-72
0=x^2 - 18x+4x-72
0=x(x-18)+4(x-18)
0=(x-18)(x+4)
x-18=0 or x+4=0
x1=18 or x2=-4
asis of symmetry: x=(x1+x2)/2
x=(18+(-4))/2
x=14/2
x=7
no
