Our y-intercept would be -7 as (0,-7) shows us the the y at this coordinate is -7
To get to (-3,0), we have to move our x-coordinate down 3.
Since we know we added 7 to the y-coordinate, we could do rise/run (7/-3) to get an answer of 2 and one third, which is our slope.
Answer: 2 1/3