a) x - 57 = 63
x = 63 + 57
x = 120
b)119 - x = 97
x = 119 -97
x = 22
c) 7.x : 28 = 5
7.x = 28x5
7.x = 140
x= 140 : 7
x= 20
d) 1751: x = 103
x = 1751 : 103
x = 17
a: x-57=63
nên x=120
b: 119-x=97
nên x=22
c: 7x:28=5
nên 7x=140
hay x=20
d: 1751:x=103
nên x=17