a + 275 = 800
a = 800 - 275
a = 525
к - 215 = 1250
к = 1250 + 215
к = 1465
6 : 25 = 62 (Предположительно, тут опечатка и должно быть b * 25 = 62)
b * 25 = 62
b = 62 / 25
b = 2.48
c * 12 = 588
c = 588 / 12
c = 49
8012 - x = 5750
x = 8012 - 5750
x = 2262
700 : x = 100
x = 700 / 100
x = 7
6280 + x = 10000
x = 10000 - 6280
x = 3720
9015 - x = 4028
x = 9015 - 4028
x = 4987
Ответ: a = 525, к = 1465, b = 2.48, c = 49, x = 2262, x = 7, x = 3720, x = 4987