(2x²-3x)²-5(2x²-3x)-6=0 3x/（x²-1）+x²

(x+1-1/1-x)÷(x-x²/x-1) (x-4/x-x-6+ x+2/x-3)÷x+1/x-3 解方程①（x+3/x-1）²-5（x+3/x-1)+6=0 ②x²-2/x+3-6x+18/x
6x+(2x²-3x)-(x²-1) f（x）=x²+3x|x-2| 4x²-{-3x²-[5x-x²-(2x²-x)]+4x},其中x=½ 代数式6x+2x²-3x+x²+1,其中x=-5 x²+3x+9/(x²-27)+6x/(9x-x²)-(x-1)/(6+2x) x(x²-1)+2x²（x+1)-3x（2x-5)计算 5x²+[x²+(5x²-2x)]-2(x²-3x),其中x=-1 (（x²-5x+6)/(12-7x+x²))²÷((x²+3x+2)/(x
(x-2)(x-3)+2(x+6)(x-5)-3(x²-7x+13)化简 ①2(x+3)(x-3)=x²+(x-1)(x+1)+2x