Iam not sure how to work this problem out? could someone me understand it?

This is kind of a tricky question as your reaction will be, well -14v and 14v add up to 0, so I can't really solve for v. But, you are kind of on the right track. If we do the above thing:


Then, we get:


And we know that:


So, we can conclude that this problem has no solutions. Meaning that there are no values of v that make the equation true.