As Sally determines the angle of rotation, since it is π, she lies on the negative x-axis. The first block then should be negative x-axis if r is positive and in the positive x-axis if r is negative.
My other reason for changing the dragged phase would be as they used the word, therefore, in the last sentence, which would mean an interference from the above statements, from the drag phase you have given the interference would be positive x-axis.
You can use the order of operations! So we start with 99^3/9. That is 99^2*11. So now let’s do 99/99, it’s 1. So 99^2*11 is 107811, so the answer is 107810.