Answer:
f(3) = - 60
Step-by-step explanation:
To evaluate f(3) substitute x = 3 into f(x), that is
f(3) = 5(3)² - 7(4(3) + 3)
= 5(9) - 7(12 + 3)
= 45 - 7(15)
= 45 - 105
= - 60
