F (x) = 3x2 - 5x - 9

g (x) = 3x - 8

Find: f (g (x))

27x^2 - 159x + 223

Step-by-step explanation:

We replace the x in f (x) by g (x):

f (g (x)) = 3 (3x - 8) ^2 - 5 (3x - 8) - 9

= 3 (9x^2 - 48x + 64) - 15x + 40 - 9

= 27x^2 - 144x + 192 - 15x + 31

= 27x^2 - 159x + 223.