The local pizzeria sold 264 slices of pizza totaling $810.00. cheese pizza costs $2.50 a slice and pepperoni pizza costs $3.25 a slice. how many slices of each pizza were sold? let c represent cheese pizza and let p represent pepperoni pizza

The equations will look like this:

(1) C + P = 264
(2) $2.5 * C + $3.25 * P = $810

Calculate from (1):
C + P = 264
P = 264 - C

Lets put P into (2):
$2.5 * C + $3.25 * P = $810
$2.5 * C + $3.25 * (264 - C) = $810
$2.5 * C  + $858 - $3.25 * C = $810
$2.5 * C  - $3.25 * C = $810 - $858
- $0.75 * C = - $48
C = 64

P = 264 - C
P = 264 - 64
P = 200

Pizzeria sold 200 slices of pepperoni pizza and 64 of cheese ones.

Where are the functions?