Newb needs brake help

[AKHiker]

Got the front brakes done well. Got the back brakes to the point they spring back open although the L side opens a little more easily. Once I press the back brake and it stops nicely, the pad on the R stays very close to the rim and the L side opens nicely.

Any ideas on how to make it stay centered? If I tighten the top bolt any more than I have it done now the brakes don't release well.