2x(2分之一x²-1)-3x(3分之一x² 3分之2)-搜答案-智慧作业帮

把等号后边分子分母同时乘以-1,这样等号两边分母可以约掉,就剩下1=3-X-1,解得X=1

(x-1/x)²=x²-2+1/x²=(x+1/x)²-4=5∴x-1/x=±√5∴x²-1/x²=(x+1/x)(x-1/x)=±3√5

已知x的二次方+3x+1=0,x+3+1/x=0x+1/x=-3(x+1/x)^2=(-3)^2x^2+2+1/x^2=9x^2+1/x^2=7x的平分+x的平方分之一+2x+x分之2=7+2*(-3

即1/(x+10)+1/(x+1)-1/(x+2)+1/(x+2)-1/(x+3)+……+1/(x+9)-1/(x+10)=2所以1/(x+1)=2x+1=1/2x=-1/2

1/x（x+3)+1/（x+3)(x+6)+1/（x+6)(x+9）=3/2（x+9)（1/3）×[3/x（x+3)+3/（x+3)(x+6）+3/（x+6）（x+9)]=3/2（x+9）（1/3)[

原式=(6x²+3x+2)/(6x³)

=[(x+3)-(x+2)]/(x+2)(x+3)+[(x+4)-(x+3)]/(x+3)(x+4)+[(x+5)-(x+4)]/(x+5)(x+4)=1/(x+2)-1/(x+3)+1/(x+3)-

1/(x+1)-1/(x+2)=1/(x+9)-1/(x+10)1/(x+1)(x+2)=1/(x+9)(x+10)所以(x+1)(x+2)=(x+9)(x+10)x²+3x+2=x

1.1/(x-1)(x-2)+1/(x-2)(x-3).+1/(x-n)(x-n-1)=[1/(x-2)-1/(x-1)]+[1/(x-3)-1/(x-2)]+.+[1/(x-n-1)-1/(x-n)

1题目是：x²/(x²-2)=3,求[1/(1-x)-1/(1+x)]/[x/(x²-1)+x]吧?如果是这样,那么由x²/(x²-2)=3得,x&#

1/x(x+1)+1/(x+1)(x+2)+.+1/(x+8)(x+9)=(2x+3)/x(x+9)1/x-1/(x+1)+1/(x+1)1/(x+2)+.+1/(x+8)-1/(x+9)=(2x+3

不用也可以算(x^4+x^2+1)/x^2=x^4/x^2+x^2/x^2+1/x^2=x^2+1+1/x^2你说的不对这里没有x+1/x而是x^2+2+1/x^2这个是完全平方即x^2+2*x*1/

再答：望采纳

(1-2的平方分之一)X(1-3的平方分之一)X(1-4的平方分之一)X.X(1-9的平方分之一)运用平方差公式=(1-1/2)(1+1/2)(1-1/3)(1+1/3)(1-1/4)(1+1/4)*

1/x(x+1)=1/x-1/(x+1)1/(x+1)(x+2)=1/(x+1)-1/(x+2)后面以此类推原式=1/x-1/(x+1)+1/(x+1)-1/(x+2)+……+1/(x+1998)-1

（1）∵x+1/x=3∴（x＋1/x）²＝9即x²＋2＋1/x²＝9∴x²＋1/x²＝7（2）由x²＋2＋1/x²＝9得x&sup

x-1/x=3两边平方x²-2×x×1/x+1/x²=3²x²-2+1/x²=9x²+1/x²=11x+1/x=6两边平方x&su

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