400x-3x^2=10000

Solution for 400x-3x^2=10000 equation:

400x-3x^2=10000

We move all terms to the left:

400x-3x^2-(10000)=0

a = -3; b = 400; c = -10000;
Δ = b2-4ac
Δ = 4002-4·(-3)·(-10000)
Δ = 40000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{40000}=200$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(400)-200}{2*-3}=\frac{-600}{-6}
=+100
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(400)+200}{2*-3}=\frac{-200}{-6}
=33+1/3
$