2a(a+28)=180

Solution for 2a(a+28)=180 equation:

2a(a+28)=180

We move all terms to the left:

2a(a+28)-(180)=0

We multiply parentheses

2a^2+56a-180=0

a = 2; b = 56; c = -180;
Δ = b2-4ac
Δ = 562-4·2·(-180)
Δ = 4576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{4576}=\sqrt{16*286}=\sqrt{16}*\sqrt{286}=4\sqrt{286}$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(56)-4\sqrt{286}}{2*2}=\frac{-56-4\sqrt{286}}{4}
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(56)+4\sqrt{286}}{2*2}=\frac{-56+4\sqrt{286}}{4}
$