the second is easy there are only three moves white can do against the check :
1. 38.Re3 then Rxe3 wins
2. 38.Ke2 then Re3+ and after king moves Rxe1 and the should be bxf7+ kxf7 and Kxe1 and black has an extra bishop
3.Kf1 then Rh1+ follow by Rxe1+ and Bxe8 and black has two pieces more.
The first is more tricky and i dont see a clear cut move at first glance...
I'm guessing maybe c5 follow by a5 could be the moves on the first game, and then whites takes in b6 with the a pawn and must be winning, just guessing...