x^2/3=87

Solution for x^2/3=87 equation:

x^2/3=87

We move all terms to the left:

x^2/3-(87)=0

We multiply all the terms by the denominator


x^2-87*3=0

We add all the numbers together, and all the variables

x^2-261=0

a = 1; b = 0; c = -261;
Δ = b2-4ac
Δ = 02-4·1·(-261)
Δ = 1044
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:

$\sqrt{\Delta}=\sqrt{1044}=\sqrt{36*29}=\sqrt{36}*\sqrt{29}=6\sqrt{29}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-6\sqrt{29}}{2*1}=\frac{0-6\sqrt{29}}{2}
=-\frac{6\sqrt{29}}{2}
=-3\sqrt{29}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+6\sqrt{29}}{2*1}=\frac{0+6\sqrt{29}}{2}
=\frac{6\sqrt{29}}{2}
=3\sqrt{29}
$