2x(4x+15)=180

Solution for 2x(4x+15)=180 equation:

2x(4x+15)=180

We move all terms to the left:

2x(4x+15)-(180)=0

We multiply parentheses

8x^2+30x-180=0

a = 8; b = 30; c = -180;
Δ = b2-4ac
Δ = 302-4·8·(-180)
Δ = 6660
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:

$\sqrt{\Delta}=\sqrt{6660}=\sqrt{36*185}=\sqrt{36}*\sqrt{185}=6\sqrt{185}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-6\sqrt{185}}{2*8}=\frac{-30-6\sqrt{185}}{16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+6\sqrt{185}}{2*8}=\frac{-30+6\sqrt{185}}{16}
$