(3-2d)(3+2d)=8

Solution for (3-2d)(3+2d)=8 equation:

(3-2d)(3+2d)=8

We move all terms to the left:

(3-2d)(3+2d)-(8)=0

We add all the numbers together, and all the variables

(-2d+3)(2d+3)-8=0

We multiply parentheses ..

(-4d^2-6d+6d+9)-8=0

We get rid of parentheses

-4d^2-6d+6d+9-8=0

We add all the numbers together, and all the variables

-4d^2+1=0

a = -4; b = 0; c = +1;
Δ = b2-4ac
Δ = 02-4·(-4)·1
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4}{2*-4}=\frac{-4}{-8}
=1/2
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4}{2*-4}=\frac{4}{-8}
=-1/2
$