а) - 2(4b - 3) + 4(2b - 2) = - 8b + 6 + 8b - 8 = - 2

б) 15c - (c + 3) + (2c - 1) = 15c - c - 3 + 2c - 1 = 16c - 4 = 4(4c - 1)

в) 6d - (7d - (8d - (9d - 10))) = 6d - (7d - (8d - 9d + 10)) = 6d - (7d - 8d +9d - 10) = 6d - 7d + 8d - 9d + 10 = - 2d + 10 = - 2(d - 5)

г) - 3(y + 2) + 2(2y - 1) = - 3y - 6 + 4y - 2 = y - 8

д) 8x - (2x + 5) + (x - 1) = 8x - 2x - 5 + x - 1 = 7x - 6

е) 13b - (9b - (8d - (6 - b))) = 13b - (9b - (8b - 6 + b)) = 13b - (9b - (9b - 6)) = 13b - (9b - 9b + 6) = 13b - 6