(2x-20)(x-20)(10)=0

Solution for (2x-20)(x-20)(10)=0 equation:

(2x-20)(x-20)(10)=0

We multiply parentheses ..

(+2x^2-40x-20x+400)10=0

We multiply parentheses

20x^2-400x-200x+4000=0

We add all the numbers together, and all the variables

20x^2-600x+4000=0

a = 20; b = -600; c = +4000;
Δ = b2-4ac
Δ = -6002-4·20·4000
Δ = 40000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{40000}=200$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-600)-200}{2*20}=\frac{400}{40}
=10
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-600)+200}{2*20}=\frac{800}{40}
=20
$