8x(x+9)=88

Solution for 8x(x+9)=88 equation:

8x(x+9)=88

We move all terms to the left:

8x(x+9)-(88)=0

We multiply parentheses

8x^2+72x-88=0

a = 8; b = 72; c = -88;
Δ = b2-4ac
Δ = 722-4·8·(-88)
Δ = 8000
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:

$\sqrt{\Delta}=\sqrt{8000}=\sqrt{1600*5}=\sqrt{1600}*\sqrt{5}=40\sqrt{5}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(72)-40\sqrt{5}}{2*8}=\frac{-72-40\sqrt{5}}{16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(72)+40\sqrt{5}}{2*8}=\frac{-72+40\sqrt{5}}{16}
$