Parallel lines have the same slope so for the new line we know m=-7 and the point (-4,6) we will substitute this info into our line to solve for b the y intercept.
Y=-7x+b
(6)=-7(-4)+b
6=28+b
6-28=28-28+b
-22=b
Now we put it all together using the slope m=-7 and the y intercept of -22
Y=-7x-22