(w-10)(w+15)=0

Solution for (w-10)(w+15)=0 equation:

(w-10)(w+15)=0

We multiply parentheses ..

(+w^2+15w-10w-150)=0

We get rid of parentheses

w^2+15w-10w-150=0

We add all the numbers together, and all the variables

w^2+5w-150=0

a = 1; b = 5; c = -150;
Δ = b2-4ac
Δ = 52-4·1·(-150)
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-25}{2*1}=\frac{-30}{2}
=-15
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+25}{2*1}=\frac{20}{2}
=10
$