Explanation:
f(g(x)) means g(x) is embedded in f(x) as the argument or input value for f(x).
therefore,
f(g)x)) = 4(x² - 1) - 7 = 4x² - 4 - 7 = 4x² - 11
c. is the right answer
g(f(x)) is now the other way around. now f(x) is the only value for g(x) :
g(f(x)) = (4x - 7)² - 1 = 16x² - 56x + 49 - 1 = 16x² - 56x + 48
a. is the right answer