(q+5)(5q+10)=0

Solution for (q+5)(5q+10)=0 equation:

(q+5)(5q+10)=0

We multiply parentheses ..

(+5q^2+10q+25q+50)=0

We get rid of parentheses

5q^2+10q+25q+50=0

We add all the numbers together, and all the variables

5q^2+35q+50=0

a = 5; b = 35; c = +50;
Δ = b2-4ac
Δ = 352-4·5·50
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$q_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$q_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$q_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(35)-15}{2*5}=\frac{-50}{10}
=-5
$
$q_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(35)+15}{2*5}=\frac{-20}{10}
=-2
$