8-x的负倒数等于9,则x-19等于?
问题描述：
8-x的负倒数等于9,则x-19等于?
答
8-x的负倒数=1/(x-8)
1/(x-8)=9
x-8=1/9
x=8+1/9
x=73/9
x-19
=73/9-19
=-98/9