Question

55,109,?433,865,1729​

Answer 1

can you please complete the question

Answer 2

Answer:

first understand the patterns

$55 \times 2 = 110 - 1 = 109 \\ 433 \times 2 = 866 - 1 = 86 \\ 865 \times 2 = 1730 - 1 = 1729$

so a*2 -1 = b

109*2 -1 = 218-1 = 217

Explanation:

so? = 217