this problem is confusing to me. 3x-6y=5. The answer I get is 31/9 and it doesn't seem right.
Please indicate which variable is the unknown (what are you solving for?). If x and y are both unknown, you have insufficient number of equations to fully solve this system.
Without subjecting the system to conditions, x and y can be any logical objects - real scalars, complex scalars, matrices, vectors, etc...
In order to solve an equation with x number of variables you need x number of equations. You have one equation with two variables which means we cannot solve both x and y.
What are you trying to solve for and what if any information were you given besides the equation?