The $50,000 of carryover losses do NOT directly get subtracted from the $77,000 gain. The get subtracted separately and should show up on Schedule E.
If you are not seeing the separate subtraction of the $50,000 on Schedule E, then go back into the introductory part of the rental section (where you enter the address, etc. of the rental property) and be sure to check the box that you sold the property.
