七年级分式数学题

来源:百度知道 编辑:UC知道 时间:2024/05/17 18:17:07
(X+2)/(X+1)-(X+4)/(X+3)=(X+6)/(X+5)-(X+8)/(X+7)
简便算法~不要硬算~!O(∩_∩)O谢谢~

(X+2)/(X+1)-(X+4)/(X+3)=(X+6)/(X+5)-(X+8)/(X+7)
(X+1+1)/(X+1)-(X+3+1)/(X+3)=(X+5+1)/(X+5)-(X+7+1)/(X+7)
1/(x+1)-1/(x+3)=1/(x+5)-1/(x+7)
(x+5)(x+7)=(x+1)(x+3)
x^2+12x+35=x^2+4x+3
8x=-32
x=-4

朋友,称项就行,

朋友,称项就行,
回答者: 蔡武林 - 助理 三级 5-13 12:44
(X+2)/(X+1)-(X+4)/(X+3)=(X+6)/(X+5)-(X+8)/(X+7)
(X+1+1)/(X+1)-(X+3+1)/(X+3)=(X+5+1)/(X+5)-(X+7+1)/(X+7)
1/(x+1)-1/(x+3)=1/(x

原式可化简为:
1/(X+1)-1/(X+3)=1/(X+5)-1/(X+7)
得(X+1)(X+3)=(X+5)(X+7)
得8X=-32
X=-4