(0.1-x)(0.1-2x)=0

Solution for (0.1-x)(0.1-2x)=0 equation:

(0.1-x)(0.1-2x)=0

We add all the numbers together, and all the variables

(-1x+0.1)(-2x+0.1)=0

We multiply parentheses ..

(+2x^2-0.1x-0.2x+0.01)=0

We get rid of parentheses

2x^2-0.1x-0.2x+0.01=0

We add all the numbers together, and all the variables

2x^2-0.3x+0.01=0

a = 2; b = -0.3; c = +0.01;
Δ = b2-4ac
Δ = -0.32-4·2·0.01
Δ = 0.01
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{-(-0.3)-\sqrt{0.01}}{2*2}=\frac{0.3-\sqrt{0.01}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.3)+\sqrt{0.01}}{2*2}=\frac{0.3+\sqrt{0.01}}{4}
$