Answer:
f(4) = 17
Step-by-step explanation:
Given function f(x), when you want to find f(4) you just put 4 for every x in the equation of the function.
f(x) = 3x + 5 ⇒ f(4) = 3(4) + 5 = 12 + 5 = 17
g(x) = 2x² - 4 ⇒ g(4) = 2(4)² - 4 = 2•16 - 4 = 32 - 4 = 28
h(x) = -3x - 9 ⇒ h(4) = -3(4) - 9 = -12 - 9 = -21
