2x(2x+4)=60

Solution for 2x(2x+4)=60 equation:

2x(2x+4)=60

We move all terms to the left:

2x(2x+4)-(60)=0

We multiply parentheses

4x^2+8x-60=0

a = 4; b = 8; c = -60;
Δ = b2-4ac
Δ = 82-4·4·(-60)
Δ = 1024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1024}=32$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-32}{2*4}=\frac{-40}{8}
=-5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+32}{2*4}=\frac{24}{8}
=3
$