问题标题:
【已知m^2+9n^+6m+6n+10=0,求(m^2-6mn+9n^2)÷(m-3n)-(4m^2-9n^2)÷(2m-3n)的值】
问题描述:

已知m^2+9n^+6m+6n+10=0,求(m^2-6mn+9n^2)÷(m-3n)-(4m^2-9n^2)÷(2m-3n)的值

来智勇回答:
  m^2+9n^+6m+6n+10=0   (m+3)^2+(3n+1)^2=0   m+3=0且3n+1=0   所以m=-3,n=-1/3   (m^2-6mn+9n^2)÷(m-3n)-(4m^2-9n^2)÷(2m-3n)   =(m-3n)^2/(m-3n)-(2m-3n)(2m+3n)/(2m-3n)   =m-3n-(2m+3n)   =-m-6n   =3+2=5
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