8x(3x+9)=126

Solution for 8x(3x+9)=126 equation:

8x(3x+9)=126

We move all terms to the left:

8x(3x+9)-(126)=0

We multiply parentheses

24x^2+72x-126=0

a = 24; b = 72; c = -126;
Δ = b2-4ac
Δ = 722-4·24·(-126)
Δ = 17280
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:

$\sqrt{\Delta}=\sqrt{17280}=\sqrt{576*30}=\sqrt{576}*\sqrt{30}=24\sqrt{30}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(72)-24\sqrt{30}}{2*24}=\frac{-72-24\sqrt{30}}{48}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(72)+24\sqrt{30}}{2*24}=\frac{-72+24\sqrt{30}}{48}
$