The answer would be C. (He counted Yolanda's candy as his own).
This is found by multiplying 500 (starting number of candy) and .64 (percentage divided by a hundred). Thjs would guve you 320, which you would then subtract from the starting number of candy (500) to get 180. 180 is Yolanda's number of candy, which gives you the answer.
The point-slope form of the equation for a line through point (h, k) with slope m is ...
... y -k = m(x -h)
The numbers in your given equation translate to ...
... m = 3/4, (h, k) = (-2, 3)
So, we know that one point on the line is (-2, 3). Another point on the line will be 3 units up and 4 units to the right of that. (Slope = (change in y)/(change in x) = 3/4.) Then a second point on the line will be (-2+4, 3+3) = (2, 6).