1/3*n=5

Solution for 1/3*n=5 equation:

1/3*n=5

We move all terms to the left:

1/3*n-(5)=0


Domain of the equation: 3*n!=0

n!=0/1

n!=0

n∈R


We multiply all the terms by the denominator


-5*3*n+1=0

Wy multiply elements

-15n*n+1=0

Wy multiply elements

-15n^2+1=0

a = -15; b = 0; c = +1;
Δ = b2-4ac
Δ = 02-4·(-15)·1
Δ = 60
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:

$\sqrt{\Delta}=\sqrt{60}=\sqrt{4*15}=\sqrt{4}*\sqrt{15}=2\sqrt{15}$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{15}}{2*-15}=\frac{0-2\sqrt{15}}{-30}
=-\frac{2\sqrt{15}}{-30}
=-\frac{\sqrt{15}}{-15}
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{15}}{2*-15}=\frac{0+2\sqrt{15}}{-30}
=\frac{2\sqrt{15}}{-30}
=\frac{\sqrt{15}}{-15}
$