Hello tutors, can I get help with the following :

For each of the problems in this section, use the Ratio Test to determine the radius of convergence of the power series. Then use this to state the largest open interval (a,b) on which the series converges.

8. = x+ 2 + 3 + . . n + 1a n=1 OO n 9. 27 (2 - 2)" = 0+ =(2 - 2) + 2(2- 2)2+3 (2- 2)3+... n=0