x-3[20-x]=3x-7[9-x]

(x+3)/(x+2)+(x+9)/(x+8)=(x+5)/(x+4)+(x+7)/(x+6)1+(x+5)/(x+2)(x+8)=1+(x+5)/(x+4)(x+6)x=-5再问：第二步那个1是怎么

将x-7/x-9分解成1+2/(x-9)其他分式同理则原方程等价于1/x-9+1/x-5=1/x-6+1/x-81/x-6-1/x-5=1/x-9-1/x-81/(x-5)(x-6)=1/(x-8)(

这是两道题吗?1、两边同时乘(x-1)(x-2)(x-3）答案是x1=-1,x2=22、分母因式分解分别为(x-7)(2x+3)和(x-5)(x-7)然后同时乘(x-5)(x-7)(2x+3)答案是x

((X-2)(X-4)-(X-3)^2)/(X-3)(X-4)=((X-5)(X-7)-(X-6)^2)/(X-6)(X-7),-1/(X^2-7X+12)=-1/(X^2-13X+42),6X=30

设a=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)那么y=a*(x-10);那么y^=a^*(x-10)+a*(x-10)^=a^*(x-10)+a那么y

 再问：额、不懂再答： 再答：后面的看做一个整体再问：好的吧、谢谢大神再答：回来的话，请采纳再问：啊、突然明白了呢。。。

x(1+2+...+9)=x(9-8-7-...-1)x=0记得采纳啊

2x+3x+4x+5x+x+6x+7x=10028x=100x=100/28x=25/7

原式=4x-60x+3x^2=5x-140x+7x^24x^2-79x=0x=0或者x=7/4

x+x^2+x^3+x^4+x^5+x^6+x^7+x^8=（x+x^2+x^3+x^4）+（x^5+x^6+x^7+x^8）=x（1+x+x^2+x^3）+x^5（1+x+x^2+x^3）=（x+x

3x*x=1+x得6x*x*x+7x*x-5x+2000=3x^2*2x+7x^2-5x+2000=(1+x)2x+7x^2-5x+2000=9x^2-3x+2000=3(3x^2-x)+2000=3

x-60+3x=3x-63+7x4x-60=10x-634x-60+63=10x4x+3=10x3=10x-4x3=6xx=1/2

1+x+x^2+x^3=0x+x^2+x^3+x^4+x^5+x^6+x^7+x^8=(x+x^2+x^3+x^4)+(x^5+x^6+x^7+x^8)=x(1+x+x^2+x^3)+x^5(1+x+

通分得[（x-8）(x-4)-(x-9)(x-3)]/(x-3)(x-4)=[(x+7)(x+3)-(x+2)(x+8)]/(x+8)(x+3)解得5/(x-3)(x-4)=5/(x+8)(x+3),

(x+8)/(x-3)-(x-9)/(x-4)=(x+7)/(x+8)-(x+2)/(x+3)[（x-8）(x-4)-(x-9)(x-3)]/(x-3)(x-4)=[(x+7)(x+3)-(x+2)(

同分化简得32x+128/(x+1)(x+3)(x+5)(x+7)=0所以得x=-4给分吧算了好久的····

应该是-2x²,不是-3x²3x²-x=1原式=9x^4-3x³+15x³-5x²+3x²-7x+2001=3x²(3x

4x-60x+3x*x=5x-140x+7x*x4x*x-79x=0x(4x-79)=0x=0或x=79/4

#includesintjiesheng(intn)//用于计算阶乘如：3!{if(n=1)rerunn;returnn*hh(n-1)}doubledigui(intn,intx)//用以计算y=x

解(x-3)(x-7)/(x^2-8x+7)-(x-5)(x-1)/(x^2-8x+7)+(x^2-x)/(x^2-8x+7)=1x^2-10x+21-(x^2-6x+5)+x^2-x=x^2-8x+