Evaluate the function at the given value. f(a) = a^3 + 5a^2 + 10a + 12 at a = -2

Abaseball team drinks 10/4 gallons of water during a game. which mixed number represents the gallons of water consumed? a) 1 1/2 gallons b) 2 1/2 gallons c) 2 3/4 gallons d) 3 1/2 gallons