F(x)=-16x^2+72x

Solution for F(x)=-16x^2+72x equation:

(F)=-16F^2+72F

We move all terms to the left:

(F)-(-16F^2+72F)=0

We get rid of parentheses

16F^2-72F+F=0

We add all the numbers together, and all the variables

16F^2-71F=0

a = 16; b = -71; c = 0;
Δ = b2-4ac
Δ = -712-4·16·0
Δ = 5041
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5041}=71$
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-71)-71}{2*16}=\frac{0}{32}
=0
$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-71)+71}{2*16}=\frac{142}{32}
=4+7/16
$