Final answer:
To find the next term in the arithmetic sequence, add the common difference to the last term (123 + 21 = 144). We can verify that 144 is the next term by subtracting the last term from it and confirming that the difference is equal to the common difference.
Step-by-step explanation:
To find the next term of the given arithmetic sequence, we need to determine the common difference between consecutive terms.
The common difference can be found by subtracting any two consecutive terms. In this case, subtracting 39 from 60 gives us a common difference of 21.
So, to get the next term, we add 21 to the last term in the sequence: 123 + 21 = 144.
Now, let's check if 144 is indeed the next term.
We can subtract the last term from 144 to verify: 144 - 123 = 21, which is the common difference.
Since the difference is equal to the common difference, we can conclude that 144 is the next term in the arithmetic sequence.