F(b)=3b^2+8b-4

Solution for F(b)=3b^2+8b-4 equation:

(F)=3F^2+8F-4

We move all terms to the left:

(F)-(3F^2+8F-4)=0

We get rid of parentheses

-3F^2+F-8F+4=0

We add all the numbers together, and all the variables

-3F^2-7F+4=0

a = -3; b = -7; c = +4;
Δ = b2-4ac
Δ = -72-4·(-3)·4
Δ = 97
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{-(-7)-\sqrt{97}}{2*-3}=\frac{7-\sqrt{97}}{-6}
$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+\sqrt{97}}{2*-3}=\frac{7+\sqrt{97}}{-6}
$