To solve this you need 2 equations with x and y. Let's start: 5x-2=13[/*:m]
For example you should easy solve something like this, for x: 5x-2=13.
Add 2 to both sides: 5x-2+2=13+2 => 5x=15[/*:m]
Divide both sides by 5: 5x/5=15/5 => x=3[/*:m]
Use the same methodology on the equations you want to solve and try to practise by searching on Google!