Step-by-step explanation:
The sequence: 55, 57, 59, 61
The recursive formula is in the form:
d = common difference
d = next term - previous term
d = 57 - 55 = 2
d = 59 - 57 = 2
d = 61 - 59 = 2
Hence, common difference = d = 2
Substitute 2 for d in the formula: