10n^2-35n+15=0

Solution for 10n^2-35n+15=0 equation:

10n^2-35n+15=0

a = 10; b = -35; c = +15;
Δ = b2-4ac
Δ = -352-4·10·15
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{-(-35)-25}{2*10}=\frac{10}{20}
=1/2
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-35)+25}{2*10}=\frac{60}{20}
=3
$