Hi

Well,

define x = amount of medium Meat Lovers pizza

define y = amount of large Meat Lovers pizza

your profit is

x*10.95 + y*14.95

50 pizzas were sold, that means x+y = 50 (1)

Furthermore someone got 663.50$

that means

x*10.95 + y*14.95 = 663.50$ (2)

you have 2 equations, solve them

=> x = 21, y = 29

Alright?