ok i'm not just going to anwer this but, i want you to answer the following questions,
1) what is the known
2) what do we not know
3) can you convert anything into something else
4) how many equations are possible
5) is it a one solution, multiple solution, or infinite solutions
6) what solution makes the most scene
7) can it be simplified
8) can it be converted
if you need more help just come to me and we can talk