F(-2)=4x^2+2x-4

Solution for F(-2)=4x^2+2x-4 equation:

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

We move all terms to the left:

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

We add all the numbers together, and all the variables

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

We get rid of parentheses

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

We add all the numbers together, and all the variables

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

a = -4; b = -2; c = +2;
Δ = b2-4ac
Δ = -22-4·(-4)·2
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-6}{2*-4}=\frac{-4}{-8}
=1/2
$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+6}{2*-4}=\frac{8}{-8}
=-1
$