-3x^2-9x+79=7

Solution for -3x^2-9x+79=7 equation:

-3x^2-9x+79=7

We move all terms to the left:

-3x^2-9x+79-(7)=0

We add all the numbers together, and all the variables

-3x^2-9x+72=0

a = -3; b = -9; c = +72;
Δ = b2-4ac
Δ = -92-4·(-3)·72
Δ = 945
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:

$\sqrt{\Delta}=\sqrt{945}=\sqrt{9*105}=\sqrt{9}*\sqrt{105}=3\sqrt{105}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-3\sqrt{105}}{2*-3}=\frac{9-3\sqrt{105}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+3\sqrt{105}}{2*-3}=\frac{9+3\sqrt{105}}{-6}
$