Jack had $80 more than Eric. When Jack spent $30, he found that the amount of money he had left was twice s much as Eric had. How much did the boys have altogether at the beginning?
First we define variables: x: amount of money Jack has y: amount of money Eric has We write the system of equations: x = y + 80 x - 30 = 2y Solving the system we have: x = $130 y = $ 50 Therefore, the amount of money they had at the beginning is: 130 + 50 = $ 180 Answer: the boys had $ 180 altogether at the beginning
