m(m n)(m-n)-m(m n)的平方-搜答案-神马作文网

由于:mn/(m+n)=2则有：mn=2(m+n)则:原式=(3m+3n-5mn)/(-m-n+3mn)=[3(m+n)-5mn]/[-(m+n)+3mn]=[3(m+n)-10(m

原式=（2m-m）/m=m/m=1~

3m-5mn+3n/（-m）+3mn-n=【3（m+n）-5mn】/【3mn-（m+n）】=【3-5mn/（m+n）】/【3mn/（m+n）-1】=【3-5x2】/【3x2-1】=-7/5

3(m^2+mn)-4(mn-2m^2n)+mn=3m²+3mn-4mn+2m²n+mn=3m²+2m²n=m²(3+2n)

答：mn/(m+n)=2分子分母同除以mn得：1/(1/n+1/m)=21/m+1/n=1/2(3m-5mn+3n)/(-m+3mn-n)分子分母同除以mn得：=(3/n-5+3/m)/(-1/n+3

mn(m-n)-m(n-m)2=m[n(m-n)-(n-m)2]=m(mn-n2-n2+2mn-m2)=m(3mn-2n2-m2)=-m(m2-3mn+2n2)=-m(m-2n)(m-n)另外m的平方

再答：谢谢

由于:mn/(m+n)=2则有：mn=2(m+n)则:原式=(3m+3n-5mn)/(-m-n+3mn)=[3(m+n)-5mn]/[-(m+n)+3mn]=[3(m+n)-10(m+n)]/[-(m

因为m-mn=21,mn-n=15,所以：m-n=(m-mn)+(mn-n)=21+15=36m-2mn+n=(m-mn)-(mn-n)=21-15=6希望能都帮到你,追问：对不起啊.我把题发错了,m

m(m-n)(n+1)

m(m-2n)+n(2mn-m^2)=m(m-2n)+n[m(2n-m)]=m(m-2n)(n+1)

m/(m-n)-n/(m+n)+mn/(m^2-n^2)=[m(m+n)-n(m-n)]/(m+n)(m-n)+mn/(m+n)(m-n)=(m^2+mn-mn+n^2)/(m+n)(m-n)+mn/

mn(m-n)-(n-m)=mn(m-n)+(m-n)=(mn+1)(m-n)

m

原式=(m²+2mn+n²-4mn)(m²-2mn+n²+4mn)+2m²n²=(m²-2mn+n²)(m²+

-2(mn-3m平方)-{m平方-5(mn-m平方)+2mn},其中m=1,n=-2=-2mn+6m^2-m^2+5(mn-m^2)-2mn=-2mn+6m^2-m^2+5mn-5m^2-2mn=mn

m²n(m-n)-4mn(n-m)

m²n(m-n)-4mn(n-m)=m²n(m-n)+4mn(m-n)=mn(m+4)(m-n)

2[mn+(-3m)]-3(2n-mn)=2mn-6m-6n+3mn=5mn-6m-6n=5mn-6(m+n)m+n=2mn=-3=-15-12=-27

3(m^2n+mn)-4(mn-2m^2n)+mn.=3m^2n+3mn-4mn+8m^2n+mn.=11m^2n.

-9mn(m-3n+2)