How do I use the two equations to solve just for fxp or fyp?

eq1: -Fccos(alp)+Fbcos (bet)+Fxp=0
eq2: -Fcsin(alp)+Fbsin(bet)-Fc+Fyp=0

since each occurs only once, I don't see the problem.

Fxp = Fccos(alp)-Fbcos (bet)
and similarly for Fyp

The problem is I know Fc=800 but not Fb so I can't find fxp and fyp. Something needed to be done first but what?