(2a+2)(a)=60

Solution for (2a+2)(a)=60 equation:

(2a+2)(a)=60

We move all terms to the left:

(2a+2)(a)-(60)=0

We multiply parentheses

2a^2+2a-60=0

a = 2; b = 2; c = -60;
Δ = b2-4ac
Δ = 22-4·2·(-60)
Δ = 484
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{484}=22$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-22}{2*2}=\frac{-24}{4}
=-6
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+22}{2*2}=\frac{20}{4}
=5
$