Question

cho 2 so x va y >0 . biet x:y =4:5 va xy=5 . khi do x bang bao nhieu

Answer 1

x:y=4:5

=>x/y=4/5

=>x/4=y/5

đặt x/4=y/5=k

ta có :x=4k

y=5k

=>x.y=4k.5k=20.k^2=5

=>k^2=1/4

=>k=1/2

=>x/4=1/2=>x=2

=>y/5=1/2=>y=5/2