-8x(x+9)-2=-74

Solution for -8x(x+9)-2=-74 equation:

-8x(x+9)-2=-74

We move all terms to the left:

-8x(x+9)-2-(-74)=0

We add all the numbers together, and all the variables

-8x(x+9)+72=0

We multiply parentheses

-8x^2-72x+72=0

a = -8; b = -72; c = +72;
Δ = b2-4ac
Δ = -722-4·(-8)·72
Δ = 7488
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:

$\sqrt{\Delta}=\sqrt{7488}=\sqrt{576*13}=\sqrt{576}*\sqrt{13}=24\sqrt{13}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-72)-24\sqrt{13}}{2*-8}=\frac{72-24\sqrt{13}}{-16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-72)+24\sqrt{13}}{2*-8}=\frac{72+24\sqrt{13}}{-16}
$