here is the circuit:

Ok, this is what I get:

v1=27.0248V (node A)

v2=22.0248V (node B)

v3=19.8347V (node D)

v4=15.0000V (node C)

The other person is getting answer close but not exactly the same.

Here is what equations im getting:

Supernode AB: (Vb-Vc)/20+(Va-Vd)/8=1.25 simplifies to 7Vb -5Vd=55

Node D: Vd/40 + (Vd-Vc)/12 + (Vd-Va)/8=0 simplifies to 28Vd - 15Vb = 225

Knowns:

Va-Vb=5

Vc=15

Any help? Thanks in advance.