C=0.00013X^2+0.002X^2+5x+2200

Solution for C=0.00013X^2+0.002X^2+5x+2200 equation:

=0.00013C^2+0.002C^2+5C+2200

We move all terms to the left:

-(0.00013C^2+0.002C^2+5C+2200)=0

We get rid of parentheses

-0.00013C^2-0.002C^2-5C-2200=0

We add all the numbers together, and all the variables

-0.00213C^2-5C-2200=0

a = -0.00213; b = -5; c = -2200;
Δ = b2-4ac
Δ = -52-4·(-0.00213)·(-2200)
Δ = 6.256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$C_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$C_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$C_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-\sqrt{6.256}}{2*-0.00213}=\frac{5-\sqrt{6.256}}{-0.00426}
$
$C_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+\sqrt{6.256}}{2*-0.00213}=\frac{5+\sqrt{6.256}}{-0.00426}
$