5d(d+5)=-30

Solution for 5d(d+5)=-30 equation:

5d(d+5)=-30

We move all terms to the left:

5d(d+5)-(-30)=0

We add all the numbers together, and all the variables

5d(d+5)+30=0

We multiply parentheses

5d^2+25d+30=0

a = 5; b = 25; c = +30;
Δ = b2-4ac
Δ = 252-4·5·30
Δ = 25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25}=5$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-5}{2*5}=\frac{-30}{10}
=-3
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+5}{2*5}=\frac{-20}{10}
=-2
$