(2d-7)(d-12)=0

Solution for (2d-7)(d-12)=0 equation:

(2d-7)(d-12)=0

We multiply parentheses ..

(+2d^2-24d-7d+84)=0

We get rid of parentheses

2d^2-24d-7d+84=0

We add all the numbers together, and all the variables

2d^2-31d+84=0

a = 2; b = -31; c = +84;
Δ = b2-4ac
Δ = -312-4·2·84
Δ = 289
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{289}=17$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-31)-17}{2*2}=\frac{14}{4}
=3+1/2
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-31)+17}{2*2}=\frac{48}{4}
=12
$