(-3x^2-30x)-27=0

Solution for (-3x^2-30x)-27=0 equation:

(-3x^2-30x)-27=0

We get rid of parentheses

-3x^2-30x-27=0

a = -3; b = -30; c = -27;
Δ = b2-4ac
Δ = -302-4·(-3)·(-27)
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-24}{2*-3}=\frac{6}{-6}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+24}{2*-3}=\frac{54}{-6}
=-9
$