Given the sequence:
1, 5, 9, 13, ...........
a) To identify the common difference, use the formula:
d = a2 - a1
where, a2 = Second term
a1 = first term
Thus,
d = 5 - 1 = 4
Therefore, the common difference is 4
b) Write an equation to represent the sequence:
Use the arithmetic sequence formula:

where,
a1 = first term
n = number of terms
d = common diffrence
Thus the equation to represent the sequence is:

c) To find the 7th term we have:

The 7th term is 25
ANSWER: