-3x^2-57x+276=0

Solution for -3x^2-57x+276=0 equation:

-3x^2-57x+276=0

a = -3; b = -57; c = +276;
Δ = b2-4ac
Δ = -572-4·(-3)·276
Δ = 6561
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6561}=81$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-57)-81}{2*-3}=\frac{-24}{-6}
=+4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-57)+81}{2*-3}=\frac{138}{-6}
=-23
$