(m n)²-2(m²-n²) (m-n)²
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![(m n)²-2(m²-n²) (m-n)²](/uploads/image/f/14224-40-4.jpg?t=%28m+n%29%C2%B2-2%28m%C2%B2-n%C2%B2%29+%28m-n%29%C2%B2)
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
(2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)先去括号=2mn+2m+3n-3mn-2n+2m-m-4n-mn合并同类项=-2mn+3m-3n=-2mn+3(m-n)把m-n=2,
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
解(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)=-2mn+2m+3n-3mn-2n+2m-m-4n-mn=-2mn-3mn-mn+2m+2m-m+3n-2n-4n=-6mn+3
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
4-m²n²+2mn=5-(m²n²-2mn+1)=5-(mn-1)²=(√5+mn-1)(√5-mn+1)如果本题有什么不明白可以追问,
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
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
(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)=-2mn+2m+3n-3mn-2n+2m-m-4n-mn=(-2mn-3mn-mn)+(2m+2m-m)+(3n-2n-4n)=-
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
再答:原式=2m(n+1)-(n+1)2=2(m-1)(n+1)
m(m-2n)+n(2mn-m^2)=m(m-2n)+n[m(2n-m)]=m(m-2n)(n+1)
=m^2n^2×(-m^6n^3)=-m^8n^5
根据题意绝对值和完全平方非负所以mn-1=0m-n-2=0mn=1m-n=2(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)=-2mn+2m+3n-3mn-2n+2m-m-4n-m
原式=(m²+2mn+n²-4mn)(m²-2mn+n²+4mn)+2m²n²=(m²-2mn+n²)(m²+
原式=-2mn+2m+3n-3mn-2n+2n-m-4n-mn=-6mn+m-n=-6×2+4=-8
2m^2-mn-n^2=(m^2-n^2)+(m^2-mn)=(m+n)(m-n)+m(m-n)=(m-n)(m+n+m)=(m-n)(2m+n)再问:x^2+2x-15谢谢再答:x^2+2x-15=
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.