-2n^2+n+136=0

Solution for -2n^2+n+136=0 equation:

-2n^2+n+136=0

a = -2; b = 1; c = +136;
Δ = b2-4ac
Δ = 12-4·(-2)·136
Δ = 1089
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1089}=33$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-33}{2*-2}=\frac{-34}{-4}
=8+1/2
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+33}{2*-2}=\frac{32}{-4}
=-8
$