Respuesta :

Answer:

3rd and 4th options

Step-by-step explanation:

(12)

(f + g)(x)

= f(x) + g(x)

= x - 2 + 5x - 1 ← collect like terms

= 6x - 3

(13)

(g • f)(x)

= g(x) × f(x)

= - 3x(6x² - 3x) ← multiply each term in the parenthesis by - 3x

= - 18x³ + 9x²