0=5x(-2x-5)

Solution for 0=5x(-2x-5) equation:

0=5x(-2x-5)

We move all terms to the left:

0-(5x(-2x-5))=0

We add all the numbers together, and all the variables

-(5x(-2x-5))=0


We calculate terms in parentheses: -(5x(-2x-5)), so:

5x(-2x-5)

We multiply parentheses

-10x^2-25x

Back to the equation:

-(-10x^2-25x)


We get rid of parentheses

10x^2+25x=0

a = 10; b = 25; c = 0;
Δ = b2-4ac
Δ = 252-4·10·0
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-25}{2*10}=\frac{-50}{20}
=-2+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+25}{2*10}=\frac{0}{20}
=0
$