You can put this solution on YOUR website! To solve the system of equations by substitution, solve one of the equations for x or y. For example, you could easily solve the second equation for y: y=3x+8. Then substitute this in for the y in the first equation, and you will end up with all x variables: -2x+3(3x+8)=17. Now you can find out what x equals and then by plugging in the value you've found for x into either of the equations, you can find y.