0=-2x^2-80x-300

Solution for 0=-2x^2-80x-300 equation:

0=-2x^2-80x-300

We move all terms to the left:

0-(-2x^2-80x-300)=0

We add all the numbers together, and all the variables

-(-2x^2-80x-300)=0

We get rid of parentheses

2x^2+80x+300=0

a = 2; b = 80; c = +300;
Δ = b2-4ac
Δ = 802-4·2·300
Δ = 4000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{4000}=\sqrt{400*10}=\sqrt{400}*\sqrt{10}=20\sqrt{10}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(80)-20\sqrt{10}}{2*2}=\frac{-80-20\sqrt{10}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(80)+20\sqrt{10}}{2*2}=\frac{-80+20\sqrt{10}}{4}
$