已知x,y为正数,且√x(√x+√y)=3√y(√x+5√y)已知x,y为正数,且√x(√x+√y)=3√y(√x+5√y)求（2x+√xy+3y）\(x+√xy—y)的值 √x(√x+√y)=3√y(√x+5√y)x+√xy=3√xy+15yx-2√xy-15y=0(√x-5√y)(√x+ 3√y)=0因...