-3x^2+2.5X+275=0

Solution for -3x^2+2.5X+275=0 equation:

-3x^2+2.5x+275=0

a = -3; b = 2.5; c = +275;
Δ = b2-4ac
Δ = 2.52-4·(-3)·275
Δ = 3306.25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2.5)-\sqrt{3306.25}}{2*-3}=\frac{-2.5-\sqrt{3306.25}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2.5)+\sqrt{3306.25}}{2*-3}=\frac{-2.5+\sqrt{3306.25}}{-6}
$