Please explain the answers

9. The coefficient recursion relation of the solution y1 = _ ana"+2 of the differential n=0 equation xy" + (x - 1)y' - y = 0 is - an an - an (a) anti = an n + 3 (b) anti = n + 3 (c) anti = (n + 2) (n+ 3) (d) anti = n + 2 (e) None of these - an 10. The solution of the coefficient recursion relation anti = (n + 1)2, n 2 0, is an = (a) (-1)"do ao -do (b) (n!) 2 (c) (d) (-1)"do ( n!) 2 (n + 1)2 ( n + 1)2 (e) None of these 11. One solution of the differential equation x2y" + (x +x?)y' + (x -9)y = 0 has the form (a) Cant" (b) Cananti (c) _ anant2 (d) and"+3 (e) None of these n=0 n=0 n=0 n=0