Answer: 2 * sqrt(2)
I attached an image to show you what I mean
Explanation:
First add 20 on both sides
5x^(2 / 3) = 10
divide both sides by 5
x^(2 / 3) = 2
Now be reminded that the power of 2/3 is the same as x^2 cube root (to the third root)
So we now cube both sides to get rid of the cube root
x^2 = 2^3
which simplifies to x^2 = 8
We now just find the square root of both sides
so x = sqrt(8)
square root of 8 is simply sqrt(4 * 2) = sqrt(4) * sqrt(2) = 2 * sqrt(2)
So x = 2 * sqrt (2)