To find the population after a year, you can multiply 4.5x10⁸ by 1.05, as it increases by 5% per year (1.05=1+5%). To find the population after five years, you have to multiply 4.5x10⁸ by 1.05 five times.
4.5x10⁸(1.05)⁵
=574326703.125
Since you can't have a decimal amount of people, you round this number to 574326703.
Therefore, the population after five years is going to be about 574326703.