10n^2-11n-15=-18

Solution for 10n^2-11n-15=-18 equation:

10n^2-11n-15=-18

We move all terms to the left:

10n^2-11n-15-(-18)=0

We add all the numbers together, and all the variables

10n^2-11n+3=0

a = 10; b = -11; c = +3;
Δ = b2-4ac
Δ = -112-4·10·3
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-11)-1}{2*10}=\frac{10}{20}
=1/2
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-11)+1}{2*10}=\frac{12}{20}
=3/5
$