5n^2+42n-80=0

Solution for 5n^2+42n-80=0 equation:

5n^2+42n-80=0

a = 5; b = 42; c = -80;
Δ = b2-4ac
Δ = 422-4·5·(-80)
Δ = 3364
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3364}=58$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(42)-58}{2*5}=\frac{-100}{10}
=-10
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(42)+58}{2*5}=\frac{16}{10}
=1+3/5
$