-5x2+80=-20x-5

Solution for -5x2+80=-20x-5 equation:

-5x^2+80=-20x-5

We move all terms to the left:

-5x^2+80-(-20x-5)=0

We get rid of parentheses

-5x^2+20x+5+80=0

We add all the numbers together, and all the variables

-5x^2+20x+85=0

a = -5; b = 20; c = +85;
Δ = b2-4ac
Δ = 202-4·(-5)·85
Δ = 2100
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:

$\sqrt{\Delta}=\sqrt{2100}=\sqrt{100*21}=\sqrt{100}*\sqrt{21}=10\sqrt{21}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-10\sqrt{21}}{2*-5}=\frac{-20-10\sqrt{21}}{-10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+10\sqrt{21}}{2*-5}=\frac{-20+10\sqrt{21}}{-10}
$