Salut !
8x - 7x - 10 = 70
x - 10 = 70
x = 70 + 10
x = 80
13y + 15y - 24 = 60
28y - 24 = 60
28y = 60 + 24
28y = 84
y = 84 : 28
y = 3
( 7x - 24 ) : 12 + 26 = 31
( 7x - 24 ) / 12 + 26 = 31
7x - 24 + 312 = 372
7x + 288 = 372
7x = 372 - 288
7x = 84
x = 84 : 7
x = 12
32 + ( 136 - 8x ) : 4 = 64
32 + ( 126 - 8x ) / 4 = 64
32 + 4( 32 - 2x ) / 4 = 64
32 + 34 - 2x = 64
66 - 2x = 64
- 2x = 64 - 66
- 2x = - 2
x = 1
8х-7х=70+10
Х=80
2)13у+15у=60+24
28у=84
У=3
3) 7х-24/12+26=31 умножим на 12 все равенство
7х-24+312=372
7х=84
Х=12
4)32+ 136-8х/4=64 умножаем все на 4
128+136-8х=256
-8х=256-128-136
-8х=-8
Х=1