Question

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

Answer 1

2(n - 1) + 4n = 2(3n - 1)
2n - 2 + 4n = 6n -2
6n - 2 = 6n - 2 (equal)
6n - 6n = 2 - 2
0 = 0

whatever value you put into the place of n, you'll get 0 = 0