(-12)*(-a-2)-10= надобно раскрыть скобки -19*(2-x)+20= -35-12 (b-3)= -18+8(4-x)= 7-(b+14)-2b= 3b-(18-b)+8= (21-a)-(20-2a)=

(-12) * (-a - 2) - 10 = 12 * a + 24 - 10 = 12 * a + 14.
-19 * (2 - x) + 20 = 19 * x - 38 + 20 = 19 * x - 18.
-35 - 12 * (b - 3) = -35 - 12 * b + 36 = 1 - 12 * b.
-18 + 8 * (4 - x) = -18 + 32 - 8 * x = 14 - 8 * x.
7 - (b + 14) - 2 * b = 7 - b - 14 - 2 * b = -3 * b - 7.
3 * b - (18 - b) + 8 = 3 * b - 18 + b + 8 = 4 * b - 10.
(21 - a) - (20 - 2 * a) = 21 - a - 20 + 2 * a = a + 1.
-(13 + b) + (-b - 13) = -2 * b - 26.
-(7 - x) + 4 * (x - b) = 5 * x - 4 * b - 7.
-9 * (y - 4) - 12 * y = 36 - 21 * y.