1) (x,y) = no solution
2) x=-2y
-2y-y = 9
-3y = 9
y = -3
x = -2(-3)
x = 6
(x,y) = (6,-3)
If these two lines are parallel, they would have the same gradient.
Since Gradient = Rise / Run,
8 / -12 : -4 / 1
These two ratios are obviously not the same, so we can conclude the lines are not parallel.
I would suggest that you look up a conversion chart.
He would travel 6 miles every hour or so
2x=3
so substitute y=mx+c
rise/run
