8x² 4x-7=0

(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

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。。。

[1-1/(x-4)]+[1-1/(x-8)]=[1-1/(x-7)]+[1-1/(x-5)]1/(x-4)+1/(x-8)=1/(x-7)+1/(x-5)(x-4+x-8)/(x-4)(x-8)=(

x(1+2+...+9)=x(9-8-7-...-1)x=0记得采纳啊

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

即1/(x-5)+1/(x-9)=1/(x-6)+1/(x-8)(2x-14)[1/(x-5)(x-9)-1/(x-6)(x-8)]=01/(x-5)(x-9)-1/(x-6)(x-8)≠0所以2x-

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)(

这道题不用那么复杂.先移项.(x-4)/(x-5)-(x-5)/(x-6)=(x-7)/(x-8)-(x-8)/( x-9)再通分.（x-4)(x-6)/(x-5)(x-6)-(x-5)(x

首先回答:X7X-X7X=X98设被减数的百位数字是a,个位数字是b,其中(0

左右两边同乘以(X-5)(X-6)(X-8)(X-9)得到(X-4)(X-6)(X-8)(X-9)-(X-5)(X-5)(X-8)(X-9)=(X-5)(X-6)(X-7)(X-9)-(X-5)(X-

(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/(

(x-4)/(x-5)-(x-5)/(x-6)=(x-7)/(x-8)-(x-8)/(x-9)1+1/(x-5)-1-1/(x-6)=1+1/(x-8)-1-1/(x-9)1/(x-5)-1/(x-6

7/x+8/x-4/x-5/x=-8-9+5+66/x=-6x=-1

x-4/x-5-x-5/x-6=x-7/x-8-x-8/x-91+1/x-5-1-1/x-6=1+1/x-8-1-1/x-91/x-5-1/x-6=1/x-8-1/x-9-1/(x-5)(x-6)=-

(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

1,应该是x是几次幂就有几个根吧,所以应该是7+2=9个2.-7.036622145,-6.489288572,-6.200988153,-4.734373320,-4.289168546,-2.77

(x-4)/(x-5)+(x-8)/(x-9)=(x-7)/(x-8)+(x-5)/(x-6)1+1/(x-5)+1+1/(x-9)=1+1/(x-8)+1+1/(x-6)1/(x-5)+1/(x-9