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).

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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).先化简,再求值:m/(m+3)-6/(m^2-9)

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).
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).

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).
原式=m/(m+3)-6/(m+3)(m-3)/2/(m-3)
=m/(m+3)-3/(m+3)
=(m-3)/(m+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)

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

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