Question

=−4x
2
+8x+11, find f, of, minus, 3f(−3)

Answer 1

Assuming f(x) = −4x^2 + 8x + 11:

f(−3) = −4(−3)^2 + 8(−3) + 11
= −4(9) − 24 + 11
= −36 − 24 + 11
= −49.

Then 3f(−3) = 3(−49) = −147.

(If you meant −3f(−3) instead, that would be −3(−49) = 147.)