千年舟负离子板材样品:解方程解方程

来源:百度文库 编辑:中科新闻网 时间:2024/04/27 18:34:51
(x+5)÷(x+7)+(x+2)÷(x+4)=(x+4)÷(x+6)+(x+3)÷(x+5)

1-2/(x+7)+1-2/(x+4)=1-2/(x+6)+1-(1/x+5)
所以1/(x+7)+1/(x+4)=1/(x+6)+1/(x+5)
化简(2x+11)/(x^2+11x+28)=(2x+11)/(x^2=11x+30)
所以只能是2x+11=0,那么x=-5.5
ps:楼上说方程无解就是少考虑了2x+11=0的情况.

(x+5)/(x+7)+(x+2)/(x+4)=(x+4)/(x+6)+(x+3)/(x+5)

【解】2/(x+7)+2/(x+4)=2/(x+6)+2/(x+5)

(2x+11)/(x+7)(x+4)=(2x+11)/(x+6)(x+5)

(x+7)(x+4)=(x+6)(x+5)

x^2+11x+28=x^2+11x+30

遗根:2x+11=0,x=-11/2

经检验:x=-11/2是原方程根

tongshang