After one year, his principal and interest are 5000+5000*5%=5000* 1.05.
After two years, his principal and interest are 5000* 1.05 (the principal and interest in the first year is regarded as the principal in the second year) +5000* 1.05*5% (the interest in the second year) = 5000 * 1.05 2.
By analogy, the principal and interest after ten years is 5000 * 1.05 10.
1.05 10 represents the power of 1.05.