F(x)=7x^2-5x+9x

Solution for F(x)=7x^2-5x+9x equation:

(F)=7F^2-5F+9F

We move all terms to the left:

(F)-(7F^2-5F+9F)=0

We get rid of parentheses

-7F^2+F+5F-9F=0

We add all the numbers together, and all the variables

-7F^2-3F=0

a = -7; b = -3; c = 0;
Δ = b2-4ac
Δ = -32-4·(-7)·0
Δ = 9
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9}=3$
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-3}{2*-7}=\frac{0}{-14}
=0
$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+3}{2*-7}=\frac{6}{-14}
=-3/7
$