First, you can multiply the numbers to the parenthesis:
5(4c-2d) = 20c - 10d
and
-6(d-3c) = -6d + 18c
now you have:
20c - 10d + 2d - 6d + 18c = (20c + 18c) + ( -10d + 2d - 6d ) = 38c - 14d and that is the simplest form :))))
I hope this is helpful
have a nice day
