In my Circuit Analysis book, I am tasked with finding \$v_x\$ and \$v_y\$. So \$v_y\$: easy enough. It's - 6 volts. But I encounter a problem when trying to find \$v_x\$ - I can't develop enough independent equations to solve for all of the elements in a given loop.
Of the components in series, I called the topmost one \$v_c\$ and the lower one \$v_b\$. I called the rightmost component \$v_a\$.
$$ -21+7+v_x+v_a=0\\ v_x-14+v_c+v_b=0\\ -v_b-v_c+v_a=0\\ -21+7+v_x+v_c+v_b=0\\ $$
Sadly, I can show at least to of these to be the same equation (they are not indepenet of each other!) so I have literally no idea how to solve this.
This is only the second problem of this type I have ever tried to solve, that I remember.
I would really appreciate it if someone could get me out of this jam!
The book gives the answer to be 9 volts.