Several things will govern whether your answer gets up-votes or not.
a) is it correct? I'm assuming that you do provide correct answers.
b) is it first? First answers tend to get more up-votes than later ones.
c) is it complete? The more complete you can make your answer the better. Editing is good - I see that you've edited that answer.
d) is it timely? This is related to being first, but also to the time between the question being posted and your answer being posted. If don't post your answer until several days after the question then the OP might have moved on. The question will always get bumped to the home page, but this leads on to:
e) are you posting when everyone else is asleep? I don't know how international the user base of Maths is but if you answer when there aren't many people around then you won't get much attention.