(x-1)(x+1)(x2-1)

(x2+4x)/(x-1) 7/x2+x+1/x2-x=6/x2-1 化简x/x2+x除以x2+x-2/x2-1+x+1/x+2 lim(根号X2+X-根号X2+1) 计算(x3+x2+x+2)/(x2+1) 6x2-[-3x2-(x-1)] 化简 x2-1/x2-5x+6 x2次方+x/x2次方-1,分式 约分 1-x2/x2-3x-4 (1-x2)(x2-4x+5) 不等式（x2-4x-5)(x2+1) 3/x2 -3x+2-1/x-2=1/x2 -x+4/x2 -2x 通分 3x/x2-2x,2x+1/4-x2,3/2x2+4x 化简x(x2-3）+x2（x-3)-3x(x2-x-1) 化简x-1分之x+1-x2-1分之x2-2x÷x2-x-2/x2+2x+1 x2-3x+1=0 x2/(x4-x2+1) x2-5x+1=0则x2+x2/1 计算:x2-5x+6/x2-4x+3 + x2-4x+3/x2-2x+1 + x2-3x-4/1-x2