x2/3=90

Solution for x2/3=90 equation:

x2/3=90

We move all terms to the left:

x2/3-(90)=0

We multiply all the terms by the denominator


x2-90*3=0

We add all the numbers together, and all the variables

x^2-270=0

a = 1; b = 0; c = -270;
Δ = b2-4ac
Δ = 02-4·1·(-270)
Δ = 1080
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1080}=\sqrt{36*30}=\sqrt{36}*\sqrt{30}=6\sqrt{30}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-6\sqrt{30}}{2*1}=\frac{0-6\sqrt{30}}{2}
=-\frac{6\sqrt{30}}{2}
=-3\sqrt{30}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+6\sqrt{30}}{2*1}=\frac{0+6\sqrt{30}}{2}
=\frac{6\sqrt{30}}{2}
=3\sqrt{30}
$