А) 2u-3(7-2u) = 3
2u-3*7-3*(-2u) = 3
2u-21+6u = 3
2u+6u = 3+21
8u = 24
u = 24:8
u = 3
Б) 12-y = 5(4-2y)+10
12-y = 5*4+5*(-2y)+10
12-y = 20-10y+10
-y+10y = 20+10-12
9y = 18
y = 18:9
y = 2
В) 2-2(x-8) = 4x-4
2-2*x-2*(-8) = 4x-4
2-2x+16 = 4x-4
-2x-4x = -4-2-16
-6x = -22
x = -22:(-6)
x = 3⁴/₆
x = 3²/₃