2.5=k2

Solution for 2.5=k2 equation:

2.5=k2

We move all terms to the left:

2.5-(k2)=0

We add all the numbers together, and all the variables

-1k^2+2.5=0

a = -1; b = 0; c = +2.5;
Δ = b2-4ac
Δ = 02-4·(-1)·2.5
Δ = 10
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{10}}{2*-1}=\frac{0-\sqrt{10}}{-2}
=-\frac{\sqrt{}}{-2}
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{10}}{2*-1}=\frac{0+\sqrt{10}}{-2}
=\frac{\sqrt{}}{-2}
$