You are correct. You solve the system x+1 = 3y 3x-4 = 5y+1 for x and y to find that x = 5 and y = 2
As a check x+1 = 3y 5+1 = 3*2 6 = 6 ... true equation and 3x-4 = 5y+1 3*5-4 = 5*2+1 11 = 11 ... true equation Both equations are true when (x,y) = (5,2) so the answer is confirmed