Need help solving number 20 with explanation please

Using the Ratio Test In Exercises 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, and 38, use the Ratio Test to determine the convergence or divergence of the series. If the Ratio Test is inconclusive, determine the convergence or divergence of the series using other methods. 00 17. 87 n=1 Answer + 18. M 8 n! 19. (n - 1)! 4n n=1 Answer 20. 272 n=0 ( n + 2) ! n+1 21. (n + 2) 7 n=0 Answer +