(7p+4)(p-13)=0

Solution for (7p+4)(p-13)=0 equation:

(7p+4)(p-13)=0

We multiply parentheses ..

(+7p^2-91p+4p-52)=0

We get rid of parentheses

7p^2-91p+4p-52=0

We add all the numbers together, and all the variables

7p^2-87p-52=0

a = 7; b = -87; c = -52;
Δ = b2-4ac
Δ = -872-4·7·(-52)
Δ = 9025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9025}=95$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-87)-95}{2*7}=\frac{-8}{14}
=-4/7
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-87)+95}{2*7}=\frac{182}{14}
=13
$