Question 885428
Rearrange each equation into the "slope-intercept" form:
y = mx + b
where m is the slope.
.
 y = -7x-9
this one is already in the form and the slope is -7
and 
-3y = 21x-9
dividing both sides by -3
y = -7x + 3
slope is also -7
.
since BOTH equations have the same slope, they are parallel