(x+40)(x+16)=0

Solution for (x+40)(x+16)=0 equation:

(x+40)(x+16)=0

We multiply parentheses ..

(+x^2+16x+40x+640)=0

We get rid of parentheses

x^2+16x+40x+640=0

We add all the numbers together, and all the variables

x^2+56x+640=0

a = 1; b = 56; c = +640;
Δ = b2-4ac
Δ = 562-4·1·640
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(56)-24}{2*1}=\frac{-80}{2}
=-40
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(56)+24}{2*1}=\frac{-32}{2}
=-16
$