Solve the system of equations, must show all work!
x + 1 = 3y
3x - 4 = 5y - 1

The system:
x + 1 = 3 y
3 x - 4 = 5 y - 1

We can use the substitution:  x = 3 y - 1
3 * ( 3 y - 1 ) - 4 = 5 y - 1
9 y - 3 - 4 = 5 y - 1
9 y - 7 = 5 y - 1
9 y - 5 y = 7 - 1
4 y = 6
y = 6 : 4
y = 1.5
x = 3 * 1.5 - 1
x = 4.5 - 1
x = 3.5
 ( 3.5,  1.5 )