`x=4y+\sqrt(2xy)`
`⇔x-4y-\sqrt(2xy)=0`
`⇔(√x+\sqrt(2y))√x-(√x+\sqrt(2y))2\sqrt(2y))=0`
`⇔(√x+\sqrt(2y))(√x-2\sqrt(2y))=0`
`⇔√x-2\sqrt(2y)=0`(vì`√x+\sqrt(2y)>0)`
`⇔√x=2\sqrt(2y)`
`⇔x=8y`
`⇒P=((\root{3}{xy})(3\root{3}{x}-2\root{3}{y}))/(\root{2}{2xy})`
`⇔P=((\root{3}{8y^2})(3\root{3}{8y}-2\root{3}{y}))/(\root{2}{16y^2})`
`⇔P=((\root{3}{8y^2})(2(3\root{3}{y}-\root{3}{y})))/(4y)`
`⇔P=((2\root{3}{y^2}.4\root{3}{y}))/(4y)`
`⇔P=(2y)/y`
`⇔P=2`
