Elimination method: You either add or subtract the equations to get an equation in one variable.
When the coefficients of one variable are opposites you add the equations to elimante a variable and when the coefficients of one variable are equal you subtract the equations to eliminate a variable.
In this case:
We can add both equations, we get:
Since we have the x-value, we can substitute it in either of the two original equations to get y-value:
Solution for the sytem of equations:
x= 18; y=15