answer: 49
explanation:
first, substitute f(3) in the expression. you do this by substituting x for 3 in f(x) = 7 - 2x so that equation becomes f(3) = 7 - 2(3) and solve to find that f(3) = 1.
f(3) = 7-2(3)
f(3) = 7-6
f(3) = 1
then substitute this into the expression and solve
(f(3)+6)^2
(1+6)^2
(7)^2
49
