-5分之x-3=15分只3x 4-搜答案-神马作文网

(1+4/5)x=9/16x=5/16(1-7/15)x=14/25x=21/10(1+3/4)x=5/6x=10/21

x^2-3x+1=0x^2+1=3x两边同除以xx+1/x=3x^2+1/x^2=(x+1/x)^2-2=9-2=7x^4+1/x^4=(x^2+1/x^2)^2-2=49-2=47

20/29

x+1/x=3,两边同时平方得到x^2+1/x^2+2=9所以x^2+1/x^2=7x^2/(x^4+x^2+1)=1/(x^2+1/x^2+1)=1/(7+1)=1/8

x+1/x==3两边乘xx²+1=3x两边平方x^4+2x²+1=9x²x^4+x²+1=8x²所以x²/(x^4+x²+1)=1

一式无法分解二式(x+1)*(x^2+x+1)*(x^2-x+1)三式无法分解

其实第n项=n*(n+1)=n^+n;则前n项的和为n(n+1)(2n+1)/6+n(n+1)/2=n(n+1)(n+2)/3.题目：带入即可得2010/3

原式=(x+1)//(x²+1)*(x²+1)(x+1)(x-1)/(x+1)³-(x-3)/(x+1)=(x-1)/(x+1)-(x-3)/(x+1)=(x-1-x+3

X+（X+12)x5分之4=42X+0.8X+9.6=421.8X=32.4X=18X+（X+28）x4分之3=42X+0.75X+21=421.75X=63X=36X+(15+X)x5分之2=69X

应该是x＋x分之1=3吧原式=(x平方＋1＋x平方分之1)分之1=[(x+1/x)平方-1]分之1=（3平方-1）分之1=8分之1

5式相加,3（x1+x2+x3+x4+x5）=1+5-5-3+2=0所以x1+x2+x3+x4+x5=0X1+X2+X3=5,X4+X5+X1=-3,两式相加：X1+（X1+X2+X3+X4+X5）=

n（n+1）分之1=nx(n+1)分之n+1-n=n分之1-（n+1）分之1

x^2-3x+1=0x^2+1=3xx+1/x=3(x+1/x)^2=9x^2+1/x^2+2=9x^2+1/x^2=7(x^2+1/x^2)^2=49x^4+1/x^4+2=49x^4+1/x^4=

啥意思

x+1/x=3两边平方x^2+2*x*1/x+1/x^2=3^2x^2+2+1/x^2=9x^2+1/x^2=7x^2/(x^4+x^2+1)上下除以x^2=1/(x^2+1+1/x^2)=1/(7+

(x4+x2+1)/x2=x2+1+1/x2=(x+1/x)^2-2+1=9-1=8所以所求=1/8(x4=x^4,凑合看)

x平方-3x+1=0二边同除以xx-3+1/x=0x+1/x=3x^2+1/x^2=(x+1/x)^2-2=3^2-2=7x^4+1/x^4=(x^2+1/x^2)^2-2=7^2-2=47

3/4x-11/20x4=2两边乘2015x-44=4015x=44+4015x=84x=5.6

1.(x+1)/(x-1)-4/(x²-1)=1都乘以(x+1)(x-1)得到(x+1)²-4=x²-1x=1代人检验是增跟,原方程无解.2.(3x+4)/(3x-5)+