F(x)=3x^2-7x-4

Solution for F(x)=3x^2-7x-4 equation:

(F)=3F^2-7F-4

We move all terms to the left:

(F)-(3F^2-7F-4)=0

We get rid of parentheses

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

We add all the numbers together, and all the variables

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

a = -3; b = 8; c = +4;
Δ = b2-4ac
Δ = 82-4·(-3)·4
Δ = 112
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{112}=\sqrt{16*7}=\sqrt{16}*\sqrt{7}=4\sqrt{7}$
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-4\sqrt{7}}{2*-3}=\frac{-8-4\sqrt{7}}{-6}
$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+4\sqrt{7}}{2*-3}=\frac{-8+4\sqrt{7}}{-6}
$