Question

3c-7d=-3

2c+6d=-34

Answer 1

from the 2nd:

2c + 6d = -34
c + 3d = -17
c = -3d-17
plug into the 1st:
3(-3d-17) - 7d = -3
-9d - 51 - 7d = -3
-16d = 48
d = -3
then c = -3(-3) - 17 = -8

c = -8 , d = -3