(120-p)(p-60)=0

Solution for (120-p)(p-60)=0 equation:

(120-p)(p-60)=0

We add all the numbers together, and all the variables

(-1p+120)(p-60)=0

We multiply parentheses ..

(-1p^2+60p+120p-7200)=0

We get rid of parentheses

-1p^2+60p+120p-7200=0

We add all the numbers together, and all the variables

-1p^2+180p-7200=0

a = -1; b = 180; c = -7200;
Δ = b2-4ac
Δ = 1802-4·(-1)·(-7200)
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(180)-60}{2*-1}=\frac{-240}{-2}
=+120
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(180)+60}{2*-1}=\frac{-120}{-2}
=+60
$