Which expression is equal to f(x) · g(x)?

Answer:
C
Step-by-step explanation:
f(x) × g(x)
= [tex]\sqrt{x^2+12x+36}[/tex] × (x³ - 12)
= [tex]\sqrt{(x+6)^2}[/tex] × (x³ - 12)
= (x + 6)(x³ - 12) ← distribute the parenthesis
= [tex]x^{4}[/tex] - 12x + 6x³ - 72
= [tex]x^{4}[/tex] + 6x³ - 12x - 72