What is the equation of the function that is graphed as line a?
y = 1/3x - 2
y = -3x - 2
y = 3x + 2
y = -1/3x - 2

The answer is y=-3 - 2.

It can't be y=3x + 2 because the graph shows the y-intercept as y=-2.
It can't be y=1/3x - 2 because you are rising one and running 3 to the right which would land you at (3,-1)  which is not on the line.
It can't be -1/3x - 2 because you are rising 1 and running 3 to the left which would land you at (-3,-1) which is also not on the line,

So that leaves you with y=-3x - 2 as the answer! :)
Hope that makes sense and helps! 

I’m going to infer you said parallel.solve for yy= -1/2x+7/4lines that are parallel have the same slope, different y intercept.so we know m is -1/2then from there solve for y intercept.