(8x)(9x+5)=180

Solution for (8x)(9x+5)=180 equation:

(8x)(9x+5)=180

We move all terms to the left:

(8x)(9x+5)-(180)=0

We multiply parentheses

72x^2+40x-180=0

a = 72; b = 40; c = -180;
Δ = b2-4ac
Δ = 402-4·72·(-180)
Δ = 53440
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:

$\sqrt{\Delta}=\sqrt{53440}=\sqrt{64*835}=\sqrt{64}*\sqrt{835}=8\sqrt{835}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(40)-8\sqrt{835}}{2*72}=\frac{-40-8\sqrt{835}}{144}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(40)+8\sqrt{835}}{2*72}=\frac{-40+8\sqrt{835}}{144}
$