(2d-2)(d+6)=0

Solution for (2d-2)(d+6)=0 equation:

(2d-2)(d+6)=0

We multiply parentheses ..

(+2d^2+12d-2d-12)=0

We get rid of parentheses

2d^2+12d-2d-12=0

We add all the numbers together, and all the variables

2d^2+10d-12=0

a = 2; b = 10; c = -12;
Δ = b2-4ac
Δ = 102-4·2·(-12)
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-14}{2*2}=\frac{-24}{4}
=-6
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+14}{2*2}=\frac{4}{4}
=1
$