0,215x-x^2=0,043^2

Solution for 0,215x-x^2=0,043^2 equation:

0.215x-x^2=0.043^2

We move all terms to the left:

0.215x-x^2-(0.043^2)=0

We add all the numbers together, and all the variables

-1x^2+0.215x-0.001849=0

a = -1; b = 0.215; c = -0.001849;
Δ = b2-4ac
Δ = 0.2152-4·(-1)·(-0.001849)
Δ = 0.038829
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0.215)-\sqrt{0.038829}}{2*-1}=\frac{-0.215-\sqrt{0.038829}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.215)+\sqrt{0.038829}}{2*-1}=\frac{-0.215+\sqrt{0.038829}}{-2}
$