Answer:
x^3 - 21x^2 + 147x - 343
Step-by-step explanation:
f(x) = x - 7
g(x) = x^3
g(f(x)) = (f(x))^3
g(f(x)) = (x - 7)^3
(x - 7)(x - 7)(x - 7)
(x^2 - 14x + 49)(x - 7)
x^3 - 7x^2 - 14x^2 + 98x + 49x - 343
x^3-21x^2+147x-343
g(f(x))=(x-7)^3=(x-7)(x-7)(x-7)
(x-7)(x^2-7x-7x+49)
(x-7)(x^2-14x+49)
x^3-14x^2+49x-7x^2+98x-343
x^3-14x^2-7x^2+49x+98x-343
