(3d-10)(9d+1)=0

Solution for (3d-10)(9d+1)=0 equation:

(3d-10)(9d+1)=0

We multiply parentheses ..

(+27d^2+3d-90d-10)=0

We get rid of parentheses

27d^2+3d-90d-10=0

We add all the numbers together, and all the variables

27d^2-87d-10=0

a = 27; b = -87; c = -10;
Δ = b2-4ac
Δ = -872-4·27·(-10)
Δ = 8649
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{8649}=93$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-87)-93}{2*27}=\frac{-6}{54}
=-1/9
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-87)+93}{2*27}=\frac{180}{54}
=3+1/3
$