(5w-2)(4-w)=0

Solution for (5w-2)(4-w)=0 equation:

(5w-2)(4-w)=0

We add all the numbers together, and all the variables

(5w-2)(-1w+4)=0

We multiply parentheses ..

(-5w^2+20w+2w-8)=0

We get rid of parentheses

-5w^2+20w+2w-8=0

We add all the numbers together, and all the variables

-5w^2+22w-8=0

a = -5; b = 22; c = -8;
Δ = b2-4ac
Δ = 222-4·(-5)·(-8)
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(22)-18}{2*-5}=\frac{-40}{-10}
=+4
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(22)+18}{2*-5}=\frac{-4}{-10}
=2/5
$