Question

先化简，再求值：m/(m+3)-6/(m^2-9)/2/(m-3）。

6/(m^2-9)/2/(m-3）的意思是6/(m^2-9)去除以2/(m-3）。拜托了！

Answer 1

原式=m/（m+3)-6/(m^2-9)*(m-3）/2
=m/(m+3)-6/[(m+3)(m-3)]*(m-3）/2
=m/(m+3)-3/(m+3)=（m-3）/（m+3）
在带入m的值就可以求出来了

Answer 2

原式=m/(m+3)-[6/(m+3)(m-3)]*[（m-3)/2]
=m/(m+3)-3/m+3
=m-3/m+3

Answer 3

6/(m^2-9) =6/(m+3)(m-3)

6/(m^2-9)/2/(m-3）=6/2 *1/(m+3) =3/(m+3)

m/(m+3)-6/(m^2-9)/2/(m-3)
=m/(m+3)-3/(m+3)
=(m-3)/(m+3)

Answer 4

解：原式＝m/(m+3)-6/(m+3)(m-3)/2/(m-3）
=m/(m+3)-3/(m+3)
=(m-3)/(m+3)。