x的平方-x 1分之x=7分之1-搜答案-搜搜考试网

（X的平方-x+1分之x）=7分之1得x^2-x+1=7x,所以x^2+1=8x,两边平方得x^4+2x^2+1=64x^2,所以x^4+x^2+1=63x^2,所以x^2/(x^4+x^2+1)=x

x+2分之1+x分之1=x的平方+2x分之321/(x+2)+1/x=32/(x²+2x)去分母x+x+2=32x=15检验：左边=1/17+1/15=32/255右边=32/(225+30

x平方+x分之7+x平方-x分之3=x平方-1分之61分之6应该就是6吧?x²+7/x+x²-3/x=x²-6x²+x²-x²+7/x-3/

1/x+2/(x-1)=2/(x^2-x)1/x+2/(x-1)-2/(x^2-x)=0(x-1)/x(x-1)+2x/x(x-1)-2/x(x-1)=0[(x-1)+2x-2]/x(x-1)=0(3

是求X的值吗?不晓得对不对哈,姑且一看吧　　由已知可得：

1-x分之3-x+x的平方-8x+7分之x的平方-2=1+7-x分之5-x(x-3)/(x-1)+(x²-2)/[(x-7)(x-1)]=1+(x-5)/(x-7)平方同乘以(x-1)(x-

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

x/(x²-x+1)=1/7x²-x+1=7xx²+1=8x两边平方x^4+2x²+1=64x²两边减去x²x^4+x²+1=63

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=

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

1分之6..

7/x(x+1)-6/(x+1)(x-1)=-1/x(x-1)两边乘以x(x+1)(x-1)得7(x-1)-6x=-(x+1)7x-7-6x=-x-12x=6∴x=3经检验：x=3是方程的解

两边乘以x(x-1)得3(x-1)+6x=73x-3+6x=79x=10x=10/9经检验：x=10/9是方程的解

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