1/x2-4x-1/4-16x

(x2+4x)/(x-1)(x²+4x)/(x-1)≤0x(x-1)(x+4)≤0(其中x≠1)使用序轴标根法,得：x≤-4或0≤x

约分1-x2/x2-3x-41-x2=(1-x)(1+x)x2-3x-4=(x+1)(x-4)共同约去（x+1)即可

(1-x2)(x2-4x+5)因为（x2-4x+5）是永远大于零的,它的b2-4ac

不等式（x2-4x-5)(x2+1)因为x2+1>0所以x2-4x-5（x2-4x-5)(x2+1)(x-5)(x+1)(x^2+1)0所以(x-5)(x+1)-1

先化解,在求值,(2x-x+1分子x2-2x)÷x2-4x分子x2-16,其中x满足3x2-x-1=0,在线等,求好心人帮帮忙3x²-x-1=0x+1=3x²(2x-x+1分子x2-2x)÷x2-4x分子x2-16=[2

：(x2-16)/(x2+8x+16)+x/(x-4)除以1/x2-16,其中x=根号2+2原式=(x+4)(x-4)/(x+4)^2+x/(x-4)=[(x-4)^2+x(x+4)]/(x+4)(x-4)=(16-4x)/(x+4)(x-

通分3x/x2-2x,2x+1/4-x2,3/2x2+4x3x/(x^2-2x)=3x/[x(x-2)](2x+1)/(4-x^2)=-(2x+1)/[(x+2)(x-2)]3/(2x^2+4x)=3/[2x(x+2)]所以最简公分母是2x

3/x2-3x+2-1/x-2=1/x2-x+4/x2-2x3/(x²－3x＋2)－1/(x－2)＝1/(x²－x)＋4/(x²－2x)3/[(x－1)(x－2)]－1/(x－2)＝1/x(x－1)＋4/x(x

1.(x-2/x+2)-16/x2-4=x+2/x-22.1-x-3/x-1=x2-2/x2-8x+7-5-x/7-x3.当x等于时,分式1/2x-1无意义；当x=时,分式x的绝对值-2/x-2值为零4.当x=时,分式3/2x-1与分式3/

4x2-4x+1=x2+6x+91.4x²-4x+1=x²+6x+9(2x-1)²=(x+3)²(2x-1)²-(x+3)²=0[(2x-1)+(x+3)][(2x-1)-(x+3

证明:根号(x2+2x+4)-根号(x2-x+1)要使根号(x2+2x+4)-根号(x2-x+1)则根号(x2+2x+4)≤根号(x2-x+1)+3平方得x²+2x+4≤x²-x+1+9+6√(x²-x+1)即

因式分解(x2+2x)2+2x2+4x+1(x^2+2x)^2+2x^2+4x+1=(x^2+2x)^2+2(x^2+2x)+1=(x^2+2x+1)^2=(x+1)^4(x²+2x)²+2x²+4x+1=(x

化简√(16-8x+x2)-√(x2-2x+1)(1＜x＜4)1＜x＜4√(16-8x+x^2)-√(x^2-2x+1)=√(x-4)^2-√(x-1)^2=4-x-(x-1)=5-2x

问几个分式化简的问题：a2-ab/b2-abx2+x/x2-1x2+4x/x2+8x+16x2-2x/2y-xy(a²-ab)/(b²-ab)=a(a-b)/b(b-a)=-a/b(x²+x)/(x²

计算:x2-5x+6/x2-4x+3+x2-4x+3/x2-2x+1+x2-3x-4/1-x2x2-5x+6/x2-4x+3+x2-4x+3/x2-2x+1+x2-3x-4/1-x2=(x-2)(x-3)/(x-3)(x-1)+(x-3)(

（x+2)(x2-2x+4)+（x-1)(x2+x+1),其中x=-三分之二原式=x3+8+x3-1=2x3+7=-16/27+7=173/7

(x+1)(x2-x+1)+(x-2)(x2+2x+4),其中x=-3/2(x+1)(x2-x+1)+(x-2)(x2+2x+4),=(x³+1)+(x³-8)=2x³-7当x=-3/2时原式=-27/4-7=

分解因式:4(3x2-x-1)(x2+2x-3)-(4x2+x-4)24(3x^2-x-1)(x^2+2x-3)-(4x^2+x-4)2=4(3x^4+5x^3-12x^2+x+3)-(16x^4+8x^3-31x^2-8x+16)=-4x

x2-4x+1=0,则x+1/x=?x2+1/x2=?x²-4x+1=0x²+1=4x两边除以xx+1/x=4x²+1=4x两边平方x^4+2x²+1=16x²x^4+1=14x²

4(x2+3x+1)2-(x2+x-4)2-(x2+5x-16)24(x^2+3x+1)^2-(x^2+x-4)^2-(x^2+5x-16)^2将x看成是一个未知数,则=原式=8(5x+1)-(3x-4)2-(7x-16)2=(40x+8)