已知m+n=3 ;mn=2 求m/n+n/m

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已知m+n=3;mn=2求m/n+n/m已知m+n=3;mn=2求m/n+n/m已知m+n=3;mn=2求m/n+n/mm/n+n/m=(m^2+n^2)/mn=[(m+n)^2-2mn]/mn=(9

已知m+n=3 ;mn=2 求m/n+n/m
已知m+n=3 ;mn=2 求m/n+n/m

已知m+n=3 ;mn=2 求m/n+n/m
m/n+n/m
=(m^2+n^2)/mn
=[(m+n)^2-2mn]/mn
=(9-4)/2
=5/2

m/n+n/m
=(m^2+n^2)/(mn)
=(m^2+n^2-2mn+2mn)/(mn)
=(m+n)^2-2
=9-2
=7

m+n=3 ;(1)
mn=2 (2)
(1)÷(2)得
m/n+n/m=3/2

m/n+n/m=(m^2+n^2)/mn=[(m+n)^2-2mn]/mn=[3^2-2*2]/2=5/2

3

(m+n)^2/mn=(m^2+n^2+2mn)/mn=m/n+n/m+2=9/2
m/n+n/m=4.5-2=2.5

m=2 n=1 2+1/2=2.5