Ответ:

1) -2(a-3b+6) = -2a+6b-12

2) (a-5b)×(-4) = 4a-5b×4 = 4a-20b

3) (3a-2b-5)×4 = 12a-8b-20

4) -(-7x-y+1) = 7x+y-1

5) 5(3-2c+d) = 15-10c+5d

6) -0.5(4+2a-b) = -2-a+0.5b