分式方程!若关于x的方程[2/(x-5)]=1-[m/(x-5)]有增根,则m的值等于什么?

Question

分式方程!
若关于x的方程[2/(x-5)]=1-[m/(x-5)]有增根,则m的值等于什么?

Answer 1

[2/(x-5)]=1-[m/(x-5)]
m/(x-5)=1-2/(x-5)=(x-5-2)/(x-5)=(x-7)/(x-5)
m=x-7
x=m+7
增根就是分母等于0
x-5=0
m+7-5=0
m=-2