I=20,000x-50x2

Solution for I=20,000x-50x2 equation:

=20.000I-50I^2

We move all terms to the left:

-(20.000I-50I^2)=0

We get rid of parentheses

50I^2-20.000I=0

We add all the numbers together, and all the variables

50I^2-20I=0

a = 50; b = -20; c = 0;
Δ = b2-4ac
Δ = -202-4·50·0
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$I_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$I_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$I_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-20}{2*50}=\frac{0}{100}
=0
$
$I_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+20}{2*50}=\frac{40}{100}
=2/5
$