Checkmate in 2 and 3 moves - with clues!

Here, black sacrifices a Rook for a Knight, but gains the game in the end! :-)
Good one.

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Next one:
In this one, even thought White has a queen to work with, Black uses his Rook, Bishop and Knight together to good effect, and to win the game in three moves:

Struggling?  Here is the first move:
1) .........Nf5 #
2) Kd2

More clues:
Then Black moves his Rook
And then his Knight again to win the game.

Let me know if you get it!

:-)