-6x2-30x+144=0

Solution for -6x2-30x+144=0 equation:

-6x^2-30x+144=0

a = -6; b = -30; c = +144;
Δ = b2-4ac
Δ = -302-4·(-6)·144
Δ = 4356
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4356}=66$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-66}{2*-6}=\frac{-36}{-12}
=+3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+66}{2*-6}=\frac{96}{-12}
=-8
$