73=c^2

Solution for 73=c^2 equation:

73=c^2

We move all terms to the left:

73-(c^2)=0

We add all the numbers together, and all the variables

-1c^2+73=0

a = -1; b = 0; c = +73;
Δ = b2-4ac
Δ = 02-4·(-1)·73
Δ = 292
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{292}=\sqrt{4*73}=\sqrt{4}*\sqrt{73}=2\sqrt{73}$
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{73}}{2*-1}=\frac{0-2\sqrt{73}}{-2}
=-\frac{2\sqrt{73}}{-2}
=-\frac{\sqrt{73}}{-1}
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{73}}{2*-1}=\frac{0+2\sqrt{73}}{-2}
=\frac{2\sqrt{73}}{-2}
=\frac{\sqrt{73}}{-1}
$