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

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

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

We multiply parentheses ..

(+28p^2+16p-49p-28)=0

We get rid of parentheses

28p^2+16p-49p-28=0

We add all the numbers together, and all the variables

28p^2-33p-28=0

a = 28; b = -33; c = -28;
Δ = b2-4ac
Δ = -332-4·28·(-28)
Δ = 4225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4225}=65$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-33)-65}{2*28}=\frac{-32}{56}
=-4/7
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-33)+65}{2*28}=\frac{98}{56}
=1+3/4
$