Question

f(x)=9x^2-5x, g(x)=19x-4
(fog)(9)

Answer 1

is it (fog)(9) or (fog)(x) ?

Answer 2

f(x) = 9x² - 5x
g(x) = 19x - 4

(f о g)(9) = 9[19(9) - 4]² - 5[19(9) - 4]
(f ο g)(9) = 9(171 - 4)² - 5(174 - 4)
(f ο g)(9) = 9(167)² - 5(167)
(f ο g)(9) = 9(27889) - 865
(f ο g)(9) = 251001 - 865
(f ο g)(9) = 250136