a) 6x + 2x + 97 = 1561
8x + 97 = 1561
8x = 1561 - 97
8x = 1464
x = 1464 : 8
x = 183
б) 344t - 137 - 2861 = 10387
344t - 2998 = 10387
344t = 10387 + 2998
344t = 13385
t = 13385 : 344
t = 39
в) 3y + 6y + 78 = 1617
9y + 78 = 1617
9y = 1617 - 78
9y = 1539
y = 1539 : 9
y = 171
г) 345m - 236m - 1972 = 63755
109m - 1972 = 63755
109m = 63755 + 1972
109m = 65727
m = 65727 : 109
m = 603
Ответ: a) x = 183; б) t = 39; B) y = 171; г) m = 603