0=5x^2-5x-10

Solution for 0=5x^2-5x-10 equation:

0=5x^2-5x-10

We move all terms to the left:

0-(5x^2-5x-10)=0

We add all the numbers together, and all the variables

-(5x^2-5x-10)=0

We get rid of parentheses

-5x^2+5x+10=0

a = -5; b = 5; c = +10;
Δ = b2-4ac
Δ = 52-4·(-5)·10
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-15}{2*-5}=\frac{-20}{-10}
=+2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+15}{2*-5}=\frac{10}{-10}
=-1
$