When you're given a parallel line, that means you know that both lines should have the same slope m. And you're given a point (x,y) so you plug in the x for in the equation and y for in the equation. Also plug in m because that was given.
y - = m(x - )
Then you can simplify the equation to get y = mx + b
We need to get the parallel line<span> into slope-intercept form</span> is y=mx+n and the POINT(A,B) and we write the new equation y-B=m(x-A)+n [https://en.wikipedia.org/wiki/Linear_equation]