To determine the cost of each item, we need to set up equations. From the problem statement, we have three unknowns so we need three equations. We set up equations as follows:
let x cost of small pizzas y cost of soda z cost of salad
two small pizzas, a liter of soda, and a salad cost $14 2x + y + z = 14
one small pizza, a liter of soda, and three salads cost $15
x + y + 3z = 15
three small pizzas, a liter of soda, and two salads cost $22 3x + y + 2z = 22
Answer: 90 Explanation: The pattern is add 3 then the next set is double. [9-6=3 then 18-9=9(or doubled)] and the pattern continues and because 45-42=3 the next number set would be 45 doubles which equals 90.
