Question 947405
What you tried to express failed to render.


Your pure text is:
x^(2/3) -5x^(1/3) ( ) 6=0


Try adjusting your equation and placement of grouping symbols, and then what you want can be more clearly read and understood.


Maybe you have something of quadratic form, as this?
x^(2/3)-5x^(1/3)=6


and you could first make a substitution like u=x^(1/3), and then u^2=x^(1/3)*x^(1/3)=x^(2/3)


allowing to say,
u^2-5u=6

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Rewrite your equation clearly in plain text, and then better help will be  possible.