▪1) (12m-5m)×4=252
7m = 252÷4
7m = 63
m = 63 ÷ 7
m = 9
▪2) (4n+3n) × 11 = 154
7n = 154 ÷ 11
7n = 14
n = 14 ÷ 7
n = 2
▪3) 45 ÷ (4m - m) = 3
3m = 45 ÷ 3
3m = 15
m = 15 ÷ 3
m = 5
▪4) (19n - 6n) ÷ 4 = 26
13n = 26 × 4
13n = 104
n = 104 ÷ 13
n = 8
▪5) (16m + 5m) ÷ 18 = 7
21m = 7 × 18
21m = 126
m = 126 ÷ 21
m = 6
▪6) (17n - 8n) × 13 = 351
9n = 351 ÷ 13
9n = 27
n = 27 ÷ 9
n = 3