Question

n/4=n+1/3n

n(3n)=4(n+1)
3n^=4n+4
3n^-4n-4=0
3(n^-4n-4)
(n-2)(n-4)

Answer 1

I assume from your 2nd line that your 1st line should have been

n/4=(n+1)/(3n)

3n^2 = 4n+4
3n^-4n-4=0
(3n + 2)(n - 2) = 0
n = -2/3 or x = 2