Help me find X and y ! x² + y² = ... and x + y = ...?

hi guys, I'm stuck on something that I really need to fix as soon as possible. here it goes :
x² + y² = 85/36 (and)
x - y = -1/6
please, If you're not willing to give me the solution, just show me some steps! and thanks in advance.
ps : i'm not that familiar with the english names in math !