(n-2)(5n-4)=0

Solution for (n-2)(5n-4)=0 equation:

(n-2)(5n-4)=0

We multiply parentheses ..

(+5n^2-4n-10n+8)=0

We get rid of parentheses

5n^2-4n-10n+8=0

We add all the numbers together, and all the variables

5n^2-14n+8=0

a = 5; b = -14; c = +8;
Δ = b2-4ac
Δ = -142-4·5·8
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-6}{2*5}=\frac{8}{10}
=4/5
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+6}{2*5}=\frac{20}{10}
=2
$