(3d+2)(3d-4)=0

Solution for (3d+2)(3d-4)=0 equation:

(3d+2)(3d-4)=0

We multiply parentheses ..

(+9d^2-12d+6d-8)=0

We get rid of parentheses

9d^2-12d+6d-8=0

We add all the numbers together, and all the variables

9d^2-6d-8=0

a = 9; b = -6; c = -8;
Δ = b2-4ac
Δ = -62-4·9·(-8)
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-18}{2*9}=\frac{-12}{18}
=-2/3
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+18}{2*9}=\frac{24}{18}
=1+1/3
$