(1-x)²=(2x+3)²
x(2x-1)=-3x(x+1)+5x²+3
化简求值 :2x(x²-x+1)-x(2x²+2x-3) x=﹣二分之一
(3x/x-1-x/x+1)×x²-1/x 其中x=根号2-2 先化简
(x+1-1/1-x)÷(x-x²/x-1) (x-4/x-x-6+ x+2/x-3)÷x+1/x-3
x²-3x+1=0.求2x³-3x²-7x+2009
6x+(2x²-3x)-(x²-1)
(2x²-2x+3)(-x³+x-1)
通分:x+2/x²-2x,x-1/x²-4x+4
计算:2x/(x-2)(x+1)÷(1-x/x+1)-x²+2x/x²-4?
(1/x²+3x+2)+(1/x²+5x+6)+(1/x²+4x+3)
已知x²+3x+1=0.(1)x²+1/x²;(2)x-1/x
x²+3x+9/(x²-27)+6x/(9x-x²)-(x-1)/(6+2x)