Because you didn't give the line, it is impossible to write it completely. However, the line would be y - 1 = m(x + 3), in which m is the slope in the line.
We know this firstly because parallel lines have the same slope. So whatever the slope is to the given line, it must match the point-slope form.
So, we'll call this mystery slope m and then use the point in plug in the point into point-slope form.
y - y1 = m(x - x1)
y - 1 = m(x - -3)
y - 1 = m(x + 3)
