4 * 5^n-1 = 5^n - 1?

Question

Make one side equal to other.

Answer 1

Let 5^[n-1] = k.
We have
4k = 5k -1, since 5^n=5*5^[n-1]
so k =1.
Hence
n-1=0;
n=1.

Answer 2

4^0 * 5^n-1 = 5^n - 1

Answer 3

I don't see a point for making one side equal to another, did you mean to say "find a solution for the equation"?

Taken literaly, you can multiply both sides by zero, then they will be equal:
0 * (4 * 5^n - 1) = 0 * (5 ^ n - 1)

Answer 4

5^(n-1)=(5^n)/5

=> 4/5*(5^n)=5^n - 1
=> (-1/5)*(5^n)=-1
=> 5^n=5
=> n=1

Answer 5

it is equal justified by the '=' sign.