C(x)=-10x^2-2500x+1000000

Solution for C(x)=-10x^2-2500x+1000000 equation:

(C)=-10C^2-2500C+1000000

We move all terms to the left:

(C)-(-10C^2-2500C+1000000)=0

We get rid of parentheses

10C^2+2500C+C-1000000=0

We add all the numbers together, and all the variables

10C^2+2501C-1000000=0

a = 10; b = 2501; c = -1000000;
Δ = b2-4ac
Δ = 25012-4·10·(-1000000)
Δ = 46255001
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{-(2501)-\sqrt{46255001}}{2*10}=\frac{-2501-\sqrt{46255001}}{20}
$
$C_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2501)+\sqrt{46255001}}{2*10}=\frac{-2501+\sqrt{46255001}}{20}
$