The equation of the line is
3y = 2x - 9
For the system to have infinite number of solutions, the equations of the lines must be equivalent i.e., the equations will result to the same equation if the coefficient of one variable in an equation is made equal to the coefficient of the same variable to the other equation. So,
The possible answers are
y = 2/3 x - 3
3/2 y = x - 9/2
Or any multiples or rearrangements of either equations.