What blood types are possible from an B positive and A positive parent?

It depends what the second gene for each parent is. Bx+ and Ax+ is the information given.

The x could be B for Bx and A for Ax. The x could also be O for both. So AA and BB or AO and BO.

In all cases the cross between AA and BB would produce AB.

For the cross between AO and BO, the result would be AB, BO, AO, and OO in a 1:1:1:1 ratio.

If the cross is AA and BO, the result would be AB and AO in a 1:1 ratio.

If the cross is BB and AO the result would be AB and BO in a 1:1 ratio.

In all cases the Rh factor would be +