0=45+2.25x-0.0635x^2

Solution for 0=45+2.25x-0.0635x^2 equation:

0=45+2.25x-0.0635x^2

We move all terms to the left:

0-(45+2.25x-0.0635x^2)=0

We add all the numbers together, and all the variables

-(45+2.25x-0.0635x^2)=0

We get rid of parentheses

0.0635x^2-2.25x-45=0

a = 0.0635; b = -2.25; c = -45;
Δ = b2-4ac
Δ = -2.252-4·0.0635·(-45)
Δ = 16.4925
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2.25)-\sqrt{16.4925}}{2*0.0635}=\frac{2.25-\sqrt{16.4925}}{0.127}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2.25)+\sqrt{16.4925}}{2*0.0635}=\frac{2.25+\sqrt{16.4925}}{0.127}
$