Question 230601
x2/3 - x1/3 -20 = 0
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I think you mean:
{{{x^(2/3) = x^(1/3) - 20 = 0}}}
This is a quadratic in x^(1/3).
{{{x^(2/3) = (x^(1/3))^2}}}
Solve it as a quadratic to find x^(1/3).
It can be factored:
= {{{(x^(1/3) - 5)*(x^(1/3) + 4)}}}
x^(1/3) = 5, -4
x = 125, -64