Answer:
Step-by-step explanation:
f(x) = [tex]x^{2}[/tex] + 24 - 12
substitute 3 inplace of x
f(3) = [tex]3^{2}[/tex] + 24 - 12
=9 + 24 - 12
21
If the question is f(x) = x2 + 24 - 12 {x*2 + 24 - 12}
now substitute 3 in place of x
f(3) = 3*2 + 24 - 12
=6 + 24 - 12
18
