In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data
f(x) = -x + 11
g(x) = 3x² - x + 14
(gof)(9) = ?
Step 02:
(gof)(x) = 3(-x+11)² - (-x+11) + 14
= 3(x² + 2(-x)(11) + 121) + x - 11 + 14
= 3(x² - 22x + 121) + x - 11 + 14
= 3x² - 66x + 363 + x - 11 + 14
= 3x² - 65x + 366
(gof)(9) = 3(9)² - 65(9) + 366
= 3(81) - 585 + 366
= 243 - 585 + 366
= 24
The answer is:
(gof)(9) = 24
