Step-by-step explanation:

g (x) = 2x^3 + 5

h (x) = -3x - 4

(g - h)(x)

= 2x^3 + 5 - (-3x - 4)

= 2x^3 + 3x + 9

(g + h)(x)

= 2x^3 + 5 + (-3x - 4)

= 2x^3 - 3x + 1

I hope this helps