F(x)=7x^2+5x-6

Solution for F(x)=7x^2+5x-6 equation:

(F)=7F^2+5F-6

We move all terms to the left:

(F)-(7F^2+5F-6)=0

We get rid of parentheses

-7F^2+F-5F+6=0

We add all the numbers together, and all the variables

-7F^2-4F+6=0

a = -7; b = -4; c = +6;
Δ = b2-4ac
Δ = -42-4·(-7)·6
Δ = 184
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:

$\sqrt{\Delta}=\sqrt{184}=\sqrt{4*46}=\sqrt{4}*\sqrt{46}=2\sqrt{46}$
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-2\sqrt{46}}{2*-7}=\frac{4-2\sqrt{46}}{-14}
$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+2\sqrt{46}}{2*-7}=\frac{4+2\sqrt{46}}{-14}
$