Puzzle confusion

Hello

Ive been sitting doing puzzles to get experience of seeing the board more and came across this one when the correct solution was black Rxe4, white Qxe4, then black Nxe4.

Im new to chess and can't figure out why you would take with rook first and take queen with knight instead of taking with knight first and keeping rook afterwards. 

Can someone help with this thank you cause Im losing my mind

By taking with the rook first, you're pinning White's queen to his king, so he's forced to trade his queen for the rook. If you were to take with the knight first, White's queen isn't pinned to his king, and White could play his queen to another square, say Qg4+, and now Black's king is being attacked.

Yeah I see that thank you you're incredible I was staring at my screen 20 mins wondering why

I'm not sure: Qg4+ might be a bad move, but you get the idea. If White's queen isn't pinned, then White has options to make various moves. Maybe castle, maybe move the queen somewhere.

Yeah I get the logic now I was gonna argue Qh5 for rook cover check but just saw the Queen to the right covering that spot I'll get better one day lmfao