My mom doesn't pay attention to me?

im 16 and i feel like my mom doesn't that much attention to me .. whenever i complain to her about changing schools because of how bad the enviorment is or how i wanna start working but she doesn't help get to anywhere she blows me off like ignoring me. But when it comes to my brothers baseball games or practices shes right on it. i wanted to better my health by going to the gym she promised me during the school year that i would go but then she just says idon'tt have any money for that but she has money to spend on my brother?. ihaven'tt really hung out or gone out the house because im stuck babysitting my brother like almost the whole day its not fair!. i dont know what to do?