WOAH! I must have barely any clue of what is this stuff, but i've seen it before, just don't really know the main part of solving these problems, although I know what to do to solve it.
Check out what I have attached, is the pathway to your success!
My first assumption is that you meant to put 2a+b+3d=0 for the first equation, instead of a c. Otherwise, you could not find only one solution for the system.
Now, the first thing you want to do is list all the variables in the same order in each equation (and simplify the -d-2d in the second one), like this:
2a + b + 3d = 0
-a + 2b - 3d = 2
a - b + d = 2