计算：（x+1)(x-1)(x2-x+1)(x2+x+1)

(x/x2-9)-(1/x2+6x+9)计算 计算x2-1/x2次方-2x+1÷x2次方+x/x-1 (x-1)(x+1)(x2+2x)计算 分式计算：2x/x2-x-2÷（1-x/x+1）-x2+2x/x2-4 计算：（1）x2+9xx2+3x+x2−9x2+6x+9 (x2+3x+9)/(x2-27)+(6x)/(9x-x2)-(x-1)/(6+2x) 计算：5x(x2-3x-1)-x2(1-x) 及急 lim(根号X2+X-根号X2+1) 化简x-1分之x+1-x2-1分之x2-2x÷x2-x-2/x2+2x+1 化简计算~1/(x2-5x+6) - 1/(4x-x2-3) - 1/(3x-x2-2) x2-5x+1=0则x2+x2/1 2( x2 +1/x2) - 9( x + 1/x) + 14 =