先化简再求值,[(m n)(2m-n)-2m(m-n)]除(二分之一n)
来源:学生作业帮助网 编辑:作业帮 时间:2024/05/15 01:34:33
原式=-2mn+6m²-m²+5(mn-m²)-2mn,=-2mn+6m²-m²+5mn-5m²-2mn,=mn,当m=1,n=-2时,原式
再答:错了再答:后面是3(m-n)再答:是15+12=27再问:谢谢了
2(mn+m)-[-(3n-mn)-m]+mn =2mn+2m+3n-mn+m+mn =2mn+3m+2n =2mn+3(m+n) ∵m+n=3,mn=-2 ∴2(mn+m)-[-(3n-m
3m平方+(2n平方-m平方)-(4n平方+5mn),=3m平方+2n平方-m平方-4n平方-5mn=2m平方-2n平方-5mn代入:2×(0.1)²-2×(-0.2)²-5×0.
(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-
-2(mn-3m^2)-[m^2-5(mn-m^2)+2mn】=-2mn+6m²-m²+5mn-5m²-2mn=mn当m=1,n=-2时原式=1×(-2)=-2
-2(mn-3m²)-[m²-5(mn-m²)+2mn]=-2mn+6m²-m²+5(mn-m²)-2mn=-2mn+6m²-m&
-2(mn-3m²)-[m²-5(mn-m²)+2mn]=-2mn+6m²-m²+5mn-5m²-2mn=mn=1x-2=-2
3m^2-mn/9m^2-6mn+n^2=m(3m-n)/(3m-n)^2=m/(3m-n)=3n/(9n-n)=3/8
把括号都拆开即可原式=-2mn+6m²-m²+5(mn-m²)-2mn=-2mn+6m²-m²+5mn-5m²-2mn=mn当m=1、n=-
2(mn-3m*)-5(mn+m*)=2mn-6m²-5mn-5m²=-3mn-11m²=-m(3n+11m)=2(3×1-11×2)=-38
-(mn-3)+3(-mn-1)-5mn=-mn+3-3mn-3-5mn=-9mn=-9*2*23=-414
-2(mn-3m^2)-m^2+5(mn-m^2)+2mn=-2mn+6m^2-m^2+5mn-5m^2+2mn=5mn当m=1,n=-2时原式=5×1×(-2)=-10再问:谢谢。你是个好人啊
[(-3mn)^2*m^3-2m^2(3mn^2)^3*0.5n]/(-3m^2n)^2=[9*m^2*n^2*m^3-2*m^2*27*m^3*n^6*0.5n]/(9*m^4n^2)=m-3mn^
原式=[(-3mn)^2*m^3-2m^2*(3mn^2)^3*n/2]÷(-3m^2n)^2=(9m^2n^2*m^3-2m^2*27m^3n^6*n/2)/(9m^4n^2)=9m^5n^2/(9
(2m-n)分之m
(mn-m²)÷(m²-2mn+n²)/mn·(m²-n²)/m²=m(n-m)×mn/(m-n)²×(m+n)(m-n)/m
=(mn)^2-4-(m-n)^2=(mn+m-n)(mn-m+n)-4把m=2n=0.5代入=(1+1.5)*(1-1.5)-4=-5.25
2m的平方-3mn-n的平方-2mn-2m的平方+5mn-2n+1=-n的平方-2n+1=-1/4+1+1=7/4
5m²n-1/2(8mn+2n²)+4(m²n+mn-2n²)=5m²n-4mn-n²+4m²n+4mn-8n²=9m&