
Actually Welcome to the concept of expo functions.
f(x) = -8(2)^x - 12 ,
for f(0) ,here substitute x = 0
so we get as ,
==> f(0) = -8(2)^0 -12
==> f(0) = -8-12
==> f(0) = -20
hence, f(0) = -20
Answer is D.Don't take out the square
1. X=-2 x=1 x=5/2
2. X=0 x=-1/5 x=4/3 x=1
3.x>-2
4.X>_8