Answer:
A
Step-by-step explanation:
(f - g)(x) = f(x) - g(x)
f(x) - g(x)
= 3x² - 2x + 4 - (5x² + 6x - 8) ← distribute parenthesis by - 1
= 3x² - 2x + 4 - 5x² - 6x + 8 ← collect like terms
= - 2x² - 8x + 12 → A
