0.00028=(0.6667-x)(1-x)

Solution for 0.00028=(0.6667-x)(1-x) equation:

0.00028=(0.6667-x)(1-x)

We move all terms to the left:

0.00028-((0.6667-x)(1-x))=0

We add all the numbers together, and all the variables

-((-1x+0.6667)(-1x+1))+0.00028=0

We multiply parentheses ..

-((+x^2-1x-0.6667x+0.6667))+0.00028=0


We calculate terms in parentheses: -((+x^2-1x-0.6667x+0.6667)), so:

(+x^2-1x-0.6667x+0.6667)

We get rid of parentheses

x^2-1x-0.6667x+0.6667

We add all the numbers together, and all the variables

x^2-1.6667x+0.6667

Back to the equation:

-(x^2-1.6667x+0.6667)


We get rid of parentheses

-x^2+1.6667x-0.6667+0.00028=0

We add all the numbers together, and all the variables

-1x^2+1.6667x-0.66642=0

a = -1; b = 1.6667; c = -0.66642;
Δ = b2-4ac
Δ = 1.66672-4·(-1)·(-0.66642)
Δ = 0.11220889
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{-(1.6667)-\sqrt{0.11220889}}{2*-1}=\frac{-1.6667-\sqrt{0.11220889}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1.6667)+\sqrt{0.11220889}}{2*-1}=\frac{-1.6667+\sqrt{0.11220889}}{-2}
$