(x^3+2x^2-x-2)(2x^2+x-1)>0(x^2-1)(x+2)(2x-1)(x+1)>0(x+1)(x-1)(x+2)(2x-1)(x+1)>0(x+1)^2(x-1)(x+2)(2x-1)>0穿根法，奇过偶不过x>1或-2
