If you thought that white could try to sacrifice an exchange in each of these examples, great job! Let’s look at the games one by one.
Black has just played f6 with the intent of undermining white’s pawn center. Black is even slightly ahead in development, and white’s rook and bishop are starting to look slightly awkward in their front-line posts. One could easily imagine the game beginning to turn against white at this point. However, he has a fantastic forcing sequence of moves to justify his play.
White has given up the exchange and a pawn, classically the equivalent of an entire piece! In return, black’s position is in ruins. His dark squared bishop, which a few moves ago was dreaming of an open long diagonal, has been relegated to passivity for the foreseeable future. His knight, which was longing for a bright future on f6, now only has the b6 square, but what then? To add to the indignity, black’s rooks are denied the e8 square by white’s bishop on h5, which looks like it will be there for a long time to come!
Interestingly, this position has been reached at least twice in grandmaster practice. The first game I could find was Eric Hansen vs Yuri Gonzalez Vidal from the Baku Olympiad in 2016. In that game, black felt the need to offer a counter sacrifice:
Black had been hoping for 21. dxe5 when he would repair his pawn structure and emerge with a massive pawn center. White ignored the offer, however, and went on to win shortly:
Let’s move on to the next example!