n^2-18n+70=0

Solution for n^2-18n+70=0 equation:

n^2-18n+70=0

a = 1; b = -18; c = +70;
Δ = b2-4ac
Δ = -182-4·1·70
Δ = 44
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:

$\sqrt{\Delta}=\sqrt{44}=\sqrt{4*11}=\sqrt{4}*\sqrt{11}=2\sqrt{11}$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-18)-2\sqrt{11}}{2*1}=\frac{18-2\sqrt{11}}{2}
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-18)+2\sqrt{11}}{2*1}=\frac{18+2\sqrt{11}}{2}
$