(8n-7)(7n-3)=0

Solution for (8n-7)(7n-3)=0 equation:

(8n-7)(7n-3)=0

We multiply parentheses ..

(+56n^2-24n-49n+21)=0

We get rid of parentheses

56n^2-24n-49n+21=0

We add all the numbers together, and all the variables

56n^2-73n+21=0

a = 56; b = -73; c = +21;
Δ = b2-4ac
Δ = -732-4·56·21
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-73)-25}{2*56}=\frac{48}{112}
=3/7
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-73)+25}{2*56}=\frac{98}{112}
=7/8
$