27=3c-3(6-2c)

-3=12y-5(2y-7)
-14=2/5(9-2b)

I'll do the first one.

27=3c-3(6-2c)

27 = 3c - 18 + 6c

27 + 18 = 9c

45 = 9c

5 = c

I'll be glad to check your answers for the other two problems.