x − y = 1. 3x = 3y + 3. First, solve the first equation for x to get x = y + 1. ... 9. y = 4x + 5. 2x + y = 17.SOLUTION: y = 4x + 5. 2x + y = 17. Substitute 4x + 5 for y in .... right, there is no solution to this systemof equations. 20. 5x − y = 5. −x + 3y = 13.