F(x)=56x2+65x-35

Solution for F(x)=56x2+65x-35 equation:

(F)=56F^2+65F-35

We move all terms to the left:

(F)-(56F^2+65F-35)=0

We get rid of parentheses

-56F^2+F-65F+35=0

We add all the numbers together, and all the variables

-56F^2-64F+35=0

a = -56; b = -64; c = +35;
Δ = b2-4ac
Δ = -642-4·(-56)·35
Δ = 11936
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:

$\sqrt{\Delta}=\sqrt{11936}=\sqrt{16*746}=\sqrt{16}*\sqrt{746}=4\sqrt{746}$
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-64)-4\sqrt{746}}{2*-56}=\frac{64-4\sqrt{746}}{-112}
$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-64)+4\sqrt{746}}{2*-56}=\frac{64+4\sqrt{746}}{-112}
$