Answer:
It looks like you wrote the equation in point-slope form perfectly!
But for part c, it seems as though x1 and y1 would represent parts of the midpoint formula. So, I would specify and say that they represent the midpoint, not just a point.
Step-by-step explanation:
1.24
i subtracted 1-1
2d+18=
Apply the PEMDAS rule in which you would have to multiply 2 to both d and 9 getting 2d+18