Question

25的X次方等于2000等于80的Y次方,求1/X+1/Y

Answer 1

25^x=2000

则

25^(xy)=2000^y=25^y*80^y

80^y=2000

则

80^(xy)=2000^x=25^x*80^x

*

(25*80)^xy=25^(x+y)*80^(x+y)

则

xy=x+y

1/X+1/Y

=(x+y)/xy

=1

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