3x^2-400x+10500=0

Solution for 3x^2-400x+10500=0 equation:

3x^2-400x+10500=0

a = 3; b = -400; c = +10500;
Δ = b2-4ac
Δ = -4002-4·3·10500
Δ = 34000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{34000}=\sqrt{400*85}=\sqrt{400}*\sqrt{85}=20\sqrt{85}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-400)-20\sqrt{85}}{2*3}=\frac{400-20\sqrt{85}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-400)+20\sqrt{85}}{2*3}=\frac{400+20\sqrt{85}}{6}
$