Bài 1
1) x + 45 = 63
x = 63 - 45
x = 18
2) x + 25 = 71
x = 71 - 25
x = 46
3) x + 69 = 82
x = 82 - 69
x = 13
4) 64 + x = 82
x = 82 - 64
x = 18
5) 29 + x = 78
x = 78 - 29
x = 49
6) 36 + x = 72
x = 72 - 36
x = 36
7) 127 + x = 371
x = 371 - 127
x = 244
8) 145 + x = 271
x = 271 - 145
x = 126
9) 219 + x = 478
x = 478 - 219
x = 259
10) x + 384 = 492
x = 492 - 384
x = 108
11) 179 + x = 368
x = 368 - 179
x = 189
Bài 2
1) x - 379 = 81
x = 81 + 379
x = 460
2) x - 73 = 129
x = 129 + 73
x = 202
3) x - 38 = 126
x = 126 + 38
x = 164
4) x - 64 = 147
x = 147 + 64
x = 211
5) x - 72 = 65
x = 65 + 72
x = 117
6) x - 89 = 43
x = 43 + 89
x = 132
7) x - 65 = 56
x = 56 + 65
x = 121
8) x - 48 = 194
x = 194 + 48
x = 242
9) x - 129 = 47
x = 47 + 129
x = 176
10) x - 291 = 183
x = 183 + 291
x = 474
