Question

数学初二分式加减

窝巢这是跪下不起了方程吃屎力直升不下
答对了我可以加分哟【跪

Answer 1

x+1／x+2+x+6／x+7=x+2／x+3+x+5／x+6
1-【1/(x+2)】+1-【1/(x+7)】=1-【1/(x+3)】+1-【1/(x+6)】
1/(x+6)-1/(x+7)=1/(x+2)-1/(x+3)
1/(x+6)(x+7)=1/(x+2)(x+3)
(x+6)(x+7)=(x+2)(x+3)
13x+42=5x+6
8x=-36
x=-4.5

不懂的，可以继续问

追问

确定咩QUQ

追答

你如果不放心的话，可以把-4.5带进方程式验一下昂~~
我是很确定的~~

追问

跪

追答

这道题没错的，相信我

Answer 2

(x+1)/(x+2)+(x+6)/(x+7)=(x+2)/(x+3)+(x+5)/(x+6)
[(x+2)-1]/(x+2)+[(x+7)-1]/(x+7)=[(x+3)-1]/(x+3)+[(x+6)-1]/(x+6)
(x+2)/(x+2)-1/(x+2)+(x+7)/(x+7)-1/(x+7)=(x+3)/(x+3)-1/(x+3)+(x+6)/(x+6)-1/(x+6)
1-1/(x+2)+1-1/(x+7)=1-1/(x+3)+1-1/(x+6)
-1/(x+2)-1/(x+7)=-1/(x+3)-1/(x+6)
1/(x+2)+1/(x+7)=1/(x+3)+1/(x+6)
1/(x+2)+1/(x+7)=1/(x+3)+1/(x+6)
(x+7)/[(x+2)(x+7)]+(x+2)/[(x+2)(x+7)]=(x+3)/[(x+3)(x+6)]+(x+6)/[(x+3)(x+6)]
(x+7+x+2)/[(x+2)(x+7)]=(x+3+x+6)/[(x+3)(x+6)]
(2x+9)/[(x+2)(x+7)]=(2x+9)/[(x+3)(x+6)]
2x+9=0
2x=-9
x=-9/2
经检验x=-9/2是方程的俀