3(p+5)(2p-5)=0

Solution for 3(p+5)(2p-5)=0 equation:

3(p+5)(2p-5)=0

We multiply parentheses ..

3(+2p^2-5p+10p-25)=0

We multiply parentheses

6p^2-15p+30p-75=0

We add all the numbers together, and all the variables

6p^2+15p-75=0

a = 6; b = 15; c = -75;
Δ = b2-4ac
Δ = 152-4·6·(-75)
Δ = 2025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2025}=45$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-45}{2*6}=\frac{-60}{12}
=-5
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+45}{2*6}=\frac{30}{12}
=2+1/2
$