105-28x=7*5

1/（x^2-7x+10)+1/(x^2-x-2)+1/(x^2+5x+4)+1/(x^2+11x+28)=[1/(x-5)-1/(x-2)+1/(x-2)-1/(x+1)+1/(x+1)-1/(x+

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

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

2x+6=5x5x-2x=63x=6x=26x-28=2x6x-2x=284x=28x=78(x-3.6)=0.8x8x-0.8x=28.87.2x=28.8x=415x-110+7x=11015x+

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

你是不是写错啦

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

/>因为：x-5/x-6+x-8/x-9=x-7/x-8+x-6/x-7,所以：1+1/(x-6)+1+1/(x-9)=1+1/(x-8)+1+1/(x-7)即：1/(x-6）+1/(x-9)=1/(

x=7a=98

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····

变形得9X—5=5X—1得4X=4得X=1再答：有不懂的再问再问：对啊……我就是想知道怎么变形……不过你这个比较详细一些……再问：右边是7-2变形，那左边是……再答：就是把未知数X移到一边再问：右边是

(x-10+2)/(x-10)+(x-6+2)/(x-6)=(x-7+2)/(x-7)+(x-9+2)/(x-9)1+2/(x-10)+1+2/(x-6)=1+2/(x-7)+1+2/(x-9)1/(

①7x=2+3x∴7x-3x=2+3x-3x∴4x=2∴4x/4=2/4∴x=1/2②3.5x=283.5x除以3.5=28除以3.5∴x=8③5(x+8)-5=6(2x-7)5x+40-5=12x-

(X-4)/(X-5)-(X-5)/(X-6)=(X-7)/(X-8)-(X-8)/(X-9)[(x-4)(x-6)-(x-5)2]/(x-5)(x-6)=[(x-7)(x-9)-(x-8)2]/(x

=x^2+10x-24+x^2+15x+56-x^2+5x+50=x^2+30x+82=4+60+82=146其实,不化简,直接代入=14*0+9*10+7*8=0+90+56=146也很简单

#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+