Question

What is the equation of the function that is graphed as line a?

Answer 1

First you find your slope which is rise/run, so, 1/3, and a line this way (/) is positive, so it's positive 1/3.
Then you see where it crosses the y axis: -1.
Plug that into y=mx+b giving you y=1/3x-1.
Your answer is D.