No 7 tlg dibantu yaa

a. (f ○ g) (x) = f (g (x))

f(g(x)) = 1/(g(x) - 8)
= 1/(9x + 2 - 8)
= 1/(9x - 6)
= 1/(3 (3x - 2))

b. (g ○ f) (x) = g(f(x))

g(f(x)) = 9f(x) + 2
= [9 × (1/(x - 8))] + 2
= (9/(x - 8)) + (2(x - 8)/(x - 8))
= (9 + 2x - 16)/(x - 8)
= (2x - 5)/(x - 8)