Bài hơi khó hiểu nka nên tui chia thành 3 trường hợp!
`**`:
`P=(sqrt{x^2}y+sqrt{y^2}x)/(sqrt{xy})`
`=(xy+yx)/(sqrt{xy})(do\,x,y>0)`
`=(2xy)/(sqrt{xy})`
`=2sqrt{xy}`
`** **`:
`P=(sqrt{x^2y}+sqrt{y^2x})/(sqrt{xy})`
`=(sqrt{xy}(sqrtx+sqrty))/(sqrt{xy})(do\,x,y>0)`
`=sqrtx+sqrty`
`** ** **`:
`P=(sqrt{x^2y+y^2x})/(sqrt{xy})`
`=(sqrt{xy}.sqrt{x+y})/(sqrt{xy})(do\,x,y>0)`
`=sqrt{x+y}`
