GWD15-23

If x>or = 0 and x=(8xy-16y^2)^ (1/2)

Ans: 4y

Please explan it.

Thanks!

这题太简单，等式两边同时平方，得出：

x^2=8xy-16y^2

x^-8xy-16y^2=0

(x-4y)^2=0

x=4y

Thanks!

I got it now