2x-x^2=0.64

Solution for 2x-x^2=0.64 equation:

2x-x^2=0.64

We move all terms to the left:

2x-x^2-(0.64)=0

We add all the numbers together, and all the variables

-1x^2+2x-0.64=0

a = -1; b = 2; c = -0.64;
Δ = b2-4ac
Δ = 22-4·(-1)·(-0.64)
Δ = 1.44
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{-(2)-\sqrt{1.44}}{2*-1}=\frac{-2-\sqrt{1.44}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+\sqrt{1.44}}{2*-1}=\frac{-2+\sqrt{1.44}}{-2}
$