1-m^2 10mn-25n^2-搜答案-大师作文网

(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,

（m+n)(m^2-mn+n^2)+(m-n)(m^2+mn+n^2)=m^3+n^3+m^3-n^3=2m^3=-2立方和公式：m^3+n^3=（m+n)(m^2-mn+n^2)立方差公式：m^3-

自己的功课自己做

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

先合并同类项,得3(m-n)-6mn+9,代入已知数据,有结果27

(-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)=-

由1/m-1/n=2得,n-m=2mn所以(3m+mn-3n)/(m-mn-n)=（mn-3*2mn)/(-mn-mn)=(-5mn)/(-2mn)=5/2

再答：原式=2m(n+1)-(n+1)2=2(m-1)(n+1)

你的符号用的不对,m分之一应该是1/m,不是m/1原式=(m^2+n^2)/(m-n)^2-(2/mn)/(1/m-1/n)^2=(m^2+n^2)/(m-n)^2-(2/mn)*[mn/(m-n)]

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

-2mn+2m+3n-3mn-2n+2m-4n-m-mn=-6mn+3m-3n=-6mn+3(m-n)=6+9=15

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

m^3-m^2n+mn^2+m^2n-mn^2+n^3+1=m³+n³+1;很高兴为您解答,skyhunter002为您答疑解惑如果本题有什么不明白可以追问,

-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

－1再答：

原式=3m^2-3mn+6n^2-2mn+2m^2-2n^2+5mn-4n^2+1=5m^2+1再问：（2x-3y+z)-3(x-2(-z+(x-y))-(3y-5z)再答：原式=2x-3y+z-3(

已知mn=-1,m-n=4则(-2mn+m+n)-(3mn+5n-5m)-(m+4n-3mn)=-2mn+m+n-3mn-5n+5m-m-4n+3mn=-2mn+5m-8n=2+20-3n=22-3n

(-2mn)^3(mn+1/2)(m^2n^2-1/2mn+1/4)=(-2mn)^3(mn+1/2)(mn-1/2)^2=(-2mn)^3(m^2n^2-1/4)(mn-1/2)=(-2mn)^3[

m^2-mn=14mn-3n^2=-2m^2+3mn-3n^2=(m^2-mn)+3mn-3n^2+mn=1+4mn-3n^2=1-2=-1

分式m-2n/m^2-2mn=1/()

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