2(x-3)(x-3)=60

Solution for 2(x-3)(x-3)=60 equation:

2(x-3)(x-3)=60

We move all terms to the left:

2(x-3)(x-3)-(60)=0

We multiply parentheses ..

2(+x^2-3x-3x+9)-60=0

We multiply parentheses

2x^2-6x-6x+18-60=0

We add all the numbers together, and all the variables

2x^2-12x-42=0

a = 2; b = -12; c = -42;
Δ = b2-4ac
Δ = -122-4·2·(-42)
Δ = 480
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:

$\sqrt{\Delta}=\sqrt{480}=\sqrt{16*30}=\sqrt{16}*\sqrt{30}=4\sqrt{30}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-4\sqrt{30}}{2*2}=\frac{12-4\sqrt{30}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+4\sqrt{30}}{2*2}=\frac{12+4\sqrt{30}}{4}
$