ответ:
1) 1729 - x = 97
- x = 97 -1729
- x = 1632
x = 1632
2) 4300 + x = 7985
x = 7985 - 4300
x = 3685
3) 8408 - x = 4805
- x = 4805 - 8408
- x = -3603
x = 3603
4) 7307 - x = 2739
- x = 2739 - 7307
- x = - 4658
x = 4658
5) x - 583 = 1301
x = 1301 + 583
x = 1884
6) 7158 - x = 4807
- x = 4807 - 7158
- x = - 2351
x = 2351
7) 1 - x = 197
- x = 197 - 1000
- x = - 803
x = 803
8) 5111 - x = 426
- x = 426 - 5111
- x = - 4685
x = 4685
9) x - 1482 = 6508
x = 6508 - 1482
x = 7990
10) x - 6671 = 1925
x = 1925 + 6671
x = 8596
11) x - 1205 = 5078
x = 5078 - 1205
x = 6283
12) 1000 - x = 273
- x = 273 - 1000
- x = - 727
x = 727
13) x - 496 = 308
x = 308 + 496
x = 804
14) 384 + x = 578
x = 578 + 384
x = 194
2x - y - z = 1
x + 3y + 4z = 6
- x - 3y - 4z = - 6
- y - z = - 1
y = 1 - z
2x - y - z = 1
2x = 1 + y + z
2x = 1 + 1 - z + z
2x = 2
x = 1
x + 2y + 3z = 5
1 + 2( 1 - z ) + 3z = 5
1 + 2 - 2z + 3z = 5
z = 5 - 3
z = 2
y = 1 - z
y = 1 - 2
y = - 1
ОТВЕТ x = 1 ; y = - 1 ; z = 2