-5x^2-8x+120=L

Solution for -5x^2-8x+120=L equation:

-5x^2-8x+120=

We move all terms to the left:

-5x^2-8x+120-()=0

We add all the numbers together, and all the variables

-5x^2-8x=0

a = -5; b = -8; c = 0;
Δ = b2-4ac
Δ = -82-4·(-5)·0
Δ = 64
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{64}=8$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-8}{2*-5}=\frac{0}{-10}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+8}{2*-5}=\frac{16}{-10}
=-1+3/5
$