Ernie earned $121.50 more than Kaylin. Tria earned $35 less than 3 times the amount Kaylin earned. Ernie, Tria, and Kaylin earned $579 in all. How much did Tria earn?
x - Ernie, y - Kaylin, z - Tria x = y + 121.50 z = 3y - 35 x + y + z = 579 ------------------------- z = 3 y - 35 => - 3 y + z = -35 y + 121.50 + y + z = 579 --------------------------------- - 3 y + z = - 35 / · ( -1 ) 2 y + z = 457.50 (we will use the elimination method) --------------------------------- 3 y - z = 35 2 y + z = 457.50 ---------------------- 5 y = 492.5, y = 492.5 : 5 = 98.5 z = 3 · 98.5 - 35 z = 260.5 Tria earned $260.5
