-6x^2+280x-1200=0

Solution for -6x^2+280x-1200=0 equation:

-6x^2+280x-1200=0

a = -6; b = 280; c = -1200;
Δ = b2-4ac
Δ = 2802-4·(-6)·(-1200)
Δ = 49600
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:

$\sqrt{\Delta}=\sqrt{49600}=\sqrt{1600*31}=\sqrt{1600}*\sqrt{31}=40\sqrt{31}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(280)-40\sqrt{31}}{2*-6}=\frac{-280-40\sqrt{31}}{-12}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(280)+40\sqrt{31}}{2*-6}=\frac{-280+40\sqrt{31}}{-12}
$