(1) Point A is greater than 0 and B is greater than 0 and A is less than 0 and B is less than 0. Then, let X 1 be less than X2 and calculate the value of f(X 1)-f(X2).

(2) shift f(x) to the left and simplify it to a(2÷3)x >-2b, and then divide it into 1a > 0 and b < 0 and a2 < 0 and b > 0.