(-5p+4)(2p-8)=0

Solution for (-5p+4)(2p-8)=0 equation:

(-5p+4)(2p-8)=0

We multiply parentheses ..

(-10p^2+40p+8p-32)=0

We get rid of parentheses

-10p^2+40p+8p-32=0

We add all the numbers together, and all the variables

-10p^2+48p-32=0

a = -10; b = 48; c = -32;
Δ = b2-4ac
Δ = 482-4·(-10)·(-32)
Δ = 1024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1024}=32$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(48)-32}{2*-10}=\frac{-80}{-20}
=+4
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(48)+32}{2*-10}=\frac{-16}{-20}
=4/5
$