0=25a^2-20a

Solution for 0=25a^2-20a equation:

0=25a^2-20a

We move all terms to the left:

0-(25a^2-20a)=0

We add all the numbers together, and all the variables

-(25a^2-20a)=0

We get rid of parentheses

-25a^2+20a=0

a = -25; b = 20; c = 0;
Δ = b2-4ac
Δ = 202-4·(-25)·0
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-20}{2*-25}=\frac{-40}{-50}
=4/5
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+20}{2*-25}=\frac{0}{-50}
=0
$