9(m n)^2-16(m-n)62
来源:学生作业帮助网 编辑:作业帮 时间:2024/09/25 05:21:06
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
=m^2-2mn+n^2+mn(前面多减一个配成完全平方,后面再加一个)=(m-n)^2+mn=(m+n)^2+5mn=81+70=151
再答:错了再答:后面是3(m-n)再答:是15+12=27再问:谢谢了
(9-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)=9-2mn+2m+3n-3mn-2n+2m-m-4n-mn=9-6mn+3m-3n=9-6mn+3(m-n)=9-6×(-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
原式=9-(m²-2mn+n²)=(3+m-n)(3-m+n)
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
3m^2-mn/9m^2-6mn+n^2=m(3m-n)/(3m-n)^2=m/(3m-n)=3n/(9n-n)=3/8
先合并同类项,得3(m-n)-6mn+9,代入已知数据,有结果27
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
(9-2mn+2m+3n)-(m+4n+mn)=9-2mn+2m+3m-m-4n-mn=9-mn+(m-n)=9-(-1)+4=14
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-2n)+n(2mn-m^2)=m(m-2n)+n[m(2n-m)]=m(m-2n)(n+1)
原式=(m²+2mn+n²-4mn)(m²-2mn+n²+4mn)+2m²n²=(m²-2mn+n²)(m²+
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)
-3m^2+9mn+12n^2=-3(m²-3mn-4n²)=-3(m+n)(m-4n)