F(x)=5x2-20x+3

Solution for F(x)=5x2-20x+3 equation:

(F)=5F^2-20F+3

We move all terms to the left:

(F)-(5F^2-20F+3)=0

We get rid of parentheses

-5F^2+F+20F-3=0

We add all the numbers together, and all the variables

-5F^2+21F-3=0

a = -5; b = 21; c = -3;
Δ = b2-4ac
Δ = 212-4·(-5)·(-3)
Δ = 381
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{-(21)-\sqrt{381}}{2*-5}=\frac{-21-\sqrt{381}}{-10}
$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(21)+\sqrt{381}}{2*-5}=\frac{-21+\sqrt{381}}{-10}
$