0=0.75p^2-70p-500

Solution for 0=0.75p^2-70p-500 equation:

0=0.75p^2-70p-500

We move all terms to the left:

0-(0.75p^2-70p-500)=0

We add all the numbers together, and all the variables

-(0.75p^2-70p-500)=0

We get rid of parentheses

-0.75p^2+70p+500=0

a = -0.75; b = 70; c = +500;
Δ = b2-4ac
Δ = 702-4·(-0.75)·500
Δ = 6400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6400}=80$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(70)-80}{2*-0.75}=\frac{-150}{-1.5}
=+100
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(70)+80}{2*-0.75}=\frac{10}{-1.5}
=-6+1/1.5
$