5n2+40n=5n

Solution for 5n2+40n=5n equation:

5n^2+40n=5n

We move all terms to the left:

5n^2+40n-(5n)=0

We add all the numbers together, and all the variables

5n^2+35n=0

a = 5; b = 35; c = 0;
Δ = b2-4ac
Δ = 352-4·5·0
Δ = 1225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1225}=35$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(35)-35}{2*5}=\frac{-70}{10}
=-7
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(35)+35}{2*5}=\frac{0}{10}
=0
$