Answer:
1) if we plug 2 in x, f (2)/(2-2)=100/0=undefined
2)ofcourse, when u plug -2 it makes it 0, f (-2)=0
3)the remainder being constant implies it is divisible by (x-1), 2x^2 (x-1)+4 (x-1), so ax^2=2x^2, a=2