Which function represents the cost of a pizza with n toppings

Correct answer is B... You can plug in values for n.  Plug in 1 for n and the out put is 12.  Plug in 2 for n and the output is 13.5

15 - 13.50 = 1.50

So each extra topping after the 1st is 1.50

C(n) = 12+ (n-1) 1.5

we use n-1 since the 1st topping is included in the 12 dollar price.

Choice B

(f - g)(x) = 5x^3 - 3

step-by-step explanation:

rearrange these functions vertically, with like terms in separate columns:

f(x) = 5x^3 - 2

g(x) =         +1

now subtract, column by column:

(f - g)(x) = 5x^3 - 3