(3d+10)(4d-8)=0

Solution for (3d+10)(4d-8)=0 equation:

(3d+10)(4d-8)=0

We multiply parentheses ..

(+12d^2-24d+40d-80)=0

We get rid of parentheses

12d^2-24d+40d-80=0

We add all the numbers together, and all the variables

12d^2+16d-80=0

a = 12; b = 16; c = -80;
Δ = b2-4ac
Δ = 162-4·12·(-80)
Δ = 4096
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4096}=64$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-64}{2*12}=\frac{-80}{24}
=-3+1/3
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+64}{2*12}=\frac{48}{24}
=2
$