find the solutions to the equation;
x^(2/5)-8x(1/5)+16=0
let u = x^(1/5)
The equation then becomes
u^2-8u+16 = 0
(u-4)^2 = 0
u = 4
so, x^(1/5) = 4
x = 4^5 = 1024
x^(2/5)-8x(1/5)+16=0
The equation then becomes
u^2-8u+16 = 0
(u-4)^2 = 0
u = 4
so, x^(1/5) = 4
x = 4^5 = 1024