20n^2+84n-1568=0

Solution for 20n^2+84n-1568=0 equation:

20n^2+84n-1568=0

a = 20; b = 84; c = -1568;
Δ = b2-4ac
Δ = 842-4·20·(-1568)
Δ = 132496
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{132496}=364$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(84)-364}{2*20}=\frac{-448}{40}
=-11+1/5
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(84)+364}{2*20}=\frac{280}{40}
=7
$