If f(x) = 4 – x2 and g(x) = 6x, which expression is equivalent to (g – f)(3)?

Question

please help with this algebra 2 question

Answer 1

(g-f)(3) = g(3)-f(3)

 

g(x) = 6x

g(3) = 6(3) = 18

 

f(x) = 4-x²

f(3) = 4-(3)² =4-9 = -5

 

g(3)-f(3) = 18 - (-5) = 18+5 = 23