You need to rearrange 9x + 3y = -22 in the form y = mx+c.
9x+3y = -22
3y = -9x - 22
y = -3x - 7.3
As long as the gradient is the same, the lines will be parallel. So you can give any number to the intercept (in this case I gave 8.3) and you will have parallel equations.
