a) 6.(x + 11) - 7.(2 - x) = 26
6x + 66 - 14 + 7x = 26
13x + 52 = 26
13x = 26 - 52
13x = -26
x = -26 : 13
x = -2
b) 2.(x - 1) - 3.(2x + 2) - 4.(2x + 3) = -2016
2x - 2 - 6x - 6 - 8x - 12 = -2016
-12x - 20 = -2016
-12x = -2016 + 20
-12x = -1996
x = (-1996) : (-12)
x = 49/3