(15 + 12 - 3) x = 240
(18 -2 +7) x 100 =
((15 -12) x2) x 10 =
((25 + 5) -20) x = 1000
(15 + 5 + 12) x 1000 =
(17 + 3 - 10) x = 1000
3 x 7 x 2 x 100 =