Given that 231n-143n=44n

assuming that n is the base in your number system

and you are finding n ....

2n^2 + 3n + 1 - (n^2 + 4n + 3) = 4n + 4
n^2 - 5n - 6 = 0
(n - 6)(n + 1) = 0
n = 6 or -1, but usually the base is a whole number

n = 6