Question

x4/3 − 8x2/3 + 15 = 0

Answer 1

That is x^4/3 - 8x^2/3 +15 =0

Answer 2

let x^2/3 = a

a^2 - 8a + 15 = 0
(a- 5)(a - 3) = 0
a= 5
a = 3

x^2/3 = 5
x^2/3 = 3

x = cuberoot 25
x = cuberoot 9