Explanation:
when lines are parallel gradiant should be the same in both equations
or m in y=mx+c
A)
1. y=-3x-6
2. y=-3x+6
therefore A is parallell
B)
1. y=44x+7/2
2.y=2/3x-17
therefore not parallel
c)
1. y=8x/7-17/7
2. y=-23x/21+30/21
therefore not parallel
d)
1. y=-8x/7+6
y=-7x/8-12
therefore not parallel
might have missed something-am tired. let me know if you have an issue.