0=-4x(4x-5)

Solution for 0=-4x(4x-5) equation:

0=-4x(4x-5)

We move all terms to the left:

0-(-4x(4x-5))=0

We add all the numbers together, and all the variables

-(-4x(4x-5))=0


We calculate terms in parentheses: -(-4x(4x-5)), so:

-4x(4x-5)

We multiply parentheses

-16x^2+20x

Back to the equation:

-(-16x^2+20x)


We get rid of parentheses

16x^2-20x=0

a = 16; b = -20; c = 0;
Δ = b2-4ac
Δ = -202-4·16·0
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-20}{2*16}=\frac{0}{32}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+20}{2*16}=\frac{40}{32}
=1+1/4
$