can you explain how you got y>0? this is my computation
then i'm left with 1>4
??? Is a better way just testing the answer choices?
See the highlighted red part. It is wrong. you can't just eliminate y at both sides, because it is an inequality.
y(y+1) > y( y - 4)
y(y+1) - y(y-4) > 0
y(y+1-y+4) > 0
so y > 0.