已知m^2+9n^2+6m+6n+10=0,求(m^2-6mn+9n^2)/(m-3n)-(4m^2-9n^2)/(2m-3n)
题目
已知m^2+9n^2+6m+6n+10=0,求(m^2-6mn+9n^2)/(m-3n)-(4m^2-9n^2)/(2m-3n)
答案
m^2+9n^2+6m+6n+10=0m^2+6m+9+9n^2+6n+1=0(m+3)^2+(3n+1)^2=0(m+3)^2=0,(3n+1)^2=0m=-3n=-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-3n-2m-3n=-m-6n=-(...
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