charlie paid $660 for 6 shirts and 4 belts. one shirt costs three times as much as one belt. if charlie bought 5 such shirts and 2 such shirts, how much would he have to pay?
let shirts is x and belt y [tex]6x + 4y = 660[/tex] [tex]x = 3y[/tex] [tex]18y + 4y = 660 \\ 22y = 660 \\ y = 30 \\ x = 90[/tex] therfore [tex]5(90) + 2(30) = 510[/tex]
