分式的加减x 1分之x平方-x 1

原式1/(x-1)+(x^2-3x)/(x+1)(x-1),然后通分得(x+1+x^2-3x)/(x+1)(x-1)=(x^2-2x+1)/(x+1)(x-1)=(x-1)(x-1)/(x-1)(x+

4x的平方+根号3x=14x的平方+根号3x-1=0若两个根分别是X1,X2,则x1+x2=-√3/4,x1*x2=-1/4X1分之X2+X2分之X1=(x2²+x1²)/(x1x

X的平方一3X十1＝0的两个实数根为X1、X2根据韦达定理得：x1+x2=3,x1*x2=1那么1/x1+1/x2=(x2+x1)/(x1x2)=3/1=3再问：太给力了，你的回答完美解决了我的问题！

x²－4x＋2＝0由韦达定理得：x1＋x2＝4,x1·x2＝2∴(1)x1+x2+3x1x2=4+3*2=10(2)x2/x1+x1/x2=(x2²+x1²)/x1x2=

5x²+x-5=0两根x1,x2,由韦达定理得x1+x2=-1/5x1x2=-5/5=-1x1²+x2²=(x1+x2)²-2x1x2=(-1/5)²

X1＋X2=-B/A=2X1*X2=C/A=1/2求得X1=1+根号2或者X1=1-根号2从而求出X2的值X1/X2+X2/X1=(X1*X1+X2*X2)/(X1X2)=6

∵x²+6x+3=0∴x1+x2=-6x1x2=3x1/x2+x2/x1=(x1+x2)²-2x1x2/x1x2=10

x1+x2=4x1x2=1/2原式=(x1+x2)²÷(x1+x2)/x1x2=x1x2(x1+x2)=2

设x1,x2是方程2x平方+4x-3=0的两个根,则x1+x2=-2x1·x2=-3/2∴x1平方+x2平方=(x1+x2)²-2x1·x2=(-2)²-2×(-3/2)=4+3=

-5x+1=0-5x=-1x=1/5(1/5)四次方=1/625+1/5=126/625所以x四次方+x=125/625

3x的平方+6x－1＝0,韦达定理得：X1+X2=-b/a=-2,X1X2=c/a=-1/31/X1+1/X2=(X1+X2)/X1X2=-2/(-1/3)=63x的平方+6x－1＝0

2/(x-y)-(x+y)/(x-y)^2=[(2x-2y)-(x+y)]/(x-y)^2=(x-3y)/(x-y)^2

由题知,x1,x2是方程4x²-4mx+m+2=0的两个实数根,判别式⊿=(4m)²-4*4*(m+2)=16[m²-m-2]≥0,即m≤-1或m≥2所以,由韦达定理x1

2x平方-5x-1=0X平方-5/2X-1/2=0X平方-5/2X=1/2X平方-5/2X+5/4的平方=1/2+5/4的平方（X-5/4）平方=33/16X-5/4=正负根号33/4X=正负根号33

x/（2-x）-（2+x）.（2-x）/（（x+2）（x+2））=x/（2-x）-（2-x）/（x+2）=（6x-4）/（4-xx

原式=1/(x+1)*[(x-3)/(x+3)^2+2/(x+3)]-x/(x+3)(x-3)=1/(x+1)[3(x+1)/(x+3)^2]-x/(x+3)(x-3)=3/(x+3)^2-x/(x+

x1+x2=-3/2x1x2=-21/x1+1/x2=（x1+x2)/x1x2=(-3/2)/(-2)=3/4x1²+x2²=(x1+x2)²-2x1x2=(-3/2)&

X1+X2=-6/2=-3X1*X2=-3/21/X1+1/X2=(X1+X2)/(X1X2)=-3/(-3/2)=2

x1+x2=4x1x2=-1(x1+x2)^2/(1/x1+1/x2)=(x1+x2)^2*x1x2/(x1+x2)=x1x2*(x1+x2)=-4

2x²+5x-3=0（2X-1)(X+3)=0所以有X1=1/2X2=-3或者X1=-3X2=1/2则|x1-x2|=3.51/x1²+1/x2²=4+1/9=37/9