w(w-7)-660=0

Solution for w(w-7)-660=0 equation:

w(w-7)-660=0

We multiply parentheses

w^2-7w-660=0

a = 1; b = -7; c = -660;
Δ = b2-4ac
Δ = -72-4·1·(-660)
Δ = 2689
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-7)-\sqrt{2689}}{2*1}=\frac{7-\sqrt{2689}}{2}
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+\sqrt{2689}}{2*1}=\frac{7+\sqrt{2689}}{2}
$