Here you have two equations with two unknown variables: If you isolate x from the second equations you get: x=(7/2)y Insert that in the first equations and solve for y: 2*(7/2)y+y=14+y y=2
Insert that value for y in one of the two equations (i chose the first): 2x+2=14+2 x=7
Therefore x=7
Hope that helped.
Actually you could start with isolating x, and then insert that in one of the two equations.