Answer:
389
Step-by-step explanation:
20 - 11 = 9
29 - 20 = 9
This is a geometric sequence with a common difference of 9.
a_1 = 11
a_2 = 11 + 9
a_3 = 11 + 2 × 9
...
a_n = 11 + (n - 1) × 9
a_43 = 11 + (43 - 1) × 9
a_43 = 11 + 42 × 9
a_43 = 389
