20n^2-148n+56=0

Solution for 20n^2-148n+56=0 equation:

20n^2-148n+56=0

a = 20; b = -148; c = +56;
Δ = b2-4ac
Δ = -1482-4·20·56
Δ = 17424
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{17424}=132$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-148)-132}{2*20}=\frac{16}{40}
=2/5
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-148)+132}{2*20}=\frac{280}{40}
=7
$