The answer would be y=5x-3.
This is the answer because you want the Y to be by itself, so you would want to get rid of the -5x.
To do this, you would have the add 5x on both sides, you would want to add 5x because you need to cancel out the -5x in order to get rid of it from that side.
y-5x=3 +5x +5x
Then you would get your answer: y=5x-3