2n^2-14n-18=0

Solution for 2n^2-14n-18=0 equation:

2n^2-14n-18=0

a = 2; b = -14; c = -18;
Δ = b2-4ac
Δ = -142-4·2·(-18)
Δ = 340
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{340}=\sqrt{4*85}=\sqrt{4}*\sqrt{85}=2\sqrt{85}$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-2\sqrt{85}}{2*2}=\frac{14-2\sqrt{85}}{4}
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+2\sqrt{85}}{2*2}=\frac{14+2\sqrt{85}}{4}
$