A) 4 - x/7 = x/9
4 - x/7 = x/9 |*63
252 - 9x = 7x
16x = 252
x = 252 : 16
x = 15.75
Ответ : 15.75
б) x + x/7 = -8
x + x/7 = -8 |*56
56x + 8x = -448
64x = -448
x = -488 : 64
x = -7
Ответ : -7
в) x/6 + x/10 = 16/15
x/6 + x/10 = 16/15 |*60
10x + 6x = 64
16x = 64
x = 4
Ответ : 4