(-2x²-x+3)(x+1)²/(x²-5x+6)≤0
(2x^2+x-3)(x+1)^2//(x^2-5x+6)>=0
(x-1)(2x+3)(x+1)^2/(x-2)(x-3)>=0
穿根法
-------（-3/2）----(-1)---------(1)-------(2)------(3)---->
+ - - + - +
不等式解集为
{x|x