-7-8n^2=-655

Solution for -7-8n^2=-655 equation:

-7-8n^2=-655

We move all terms to the left:

-7-8n^2-(-655)=0

We add all the numbers together, and all the variables

-8n^2+648=0

a = -8; b = 0; c = +648;
Δ = b2-4ac
Δ = 02-4·(-8)·648
Δ = 20736
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{20736}=144$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-144}{2*-8}=\frac{-144}{-16}
=+9
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+144}{2*-8}=\frac{144}{-16}
=-9
$