x/(7.5+2.5)+(x-10)/(7.5-2.5)=7 解之得：x=?_数学解答

x/(7.5+2.5)+(x-10)/(7.5-2.5)=7 解之得：x=?

人气：211 ℃　时间：2020-02-02 18:52:11

解答

x/(7.5+2.5)+(x-10)/(7.5-2.5)=7
x/10+(x-10)/5=7 两边乘10
x+2x-20=70
3x=70+20
3x=90
x=30