R(x)=110x-0.15x^2

Solution for R(x)=110x-0.15x^2 equation:

(R)=110R-0.15R^2

We move all terms to the left:

(R)-(110R-0.15R^2)=0

We get rid of parentheses

0.15R^2-110R+R=0

We add all the numbers together, and all the variables

0.15R^2-109R=0

a = 0.15; b = -109; c = 0;
Δ = b2-4ac
Δ = -1092-4·0.15·0
Δ = 11881
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$R_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$R_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{11881}=109$
$R_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-109)-109}{2*0.15}=\frac{0}{0.3}
=0
$
$R_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-109)+109}{2*0.15}=\frac{218}{0.3}
=726+0.20000000000002/0.3
$