б) 3(4x-1)+2 = 3 4x - 3 1 + 2 = 12x - 3 + 2 = 12x - 1

в) 8m + (m-2) - (5m+3) = 8m + m - 2 - 5m - 3 = 8m + m - 5m - 2 - 3 = 4m - 5