F(x)=2x2-8x-4

Solution for F(x)=2x2-8x-4 equation:

(F)=2F^2-8F-4

We move all terms to the left:

(F)-(2F^2-8F-4)=0

We get rid of parentheses

-2F^2+F+8F+4=0

We add all the numbers together, and all the variables

-2F^2+9F+4=0

a = -2; b = 9; c = +4;
Δ = b2-4ac
Δ = 92-4·(-2)·4
Δ = 113
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-\sqrt{113}}{2*-2}=\frac{-9-\sqrt{113}}{-4}
$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+\sqrt{113}}{2*-2}=\frac{-9+\sqrt{113}}{-4}
$