5^3=125; 2.5^2=6.25. So the answer to your first question is 125, and the second one is 6.25
Answer:
The18th term of the given sequence is -128
Explanation:
To find the 18th term of the sequence:
42, 32, 22, 12, ..., we need to find the nth term of the sequence first.
The nth term of a sequence is given be the formula:

Where a is the first term, and d is the common difference.
Here, a = 42, d = 32 - 42 = -10

To find the 18th terem, substitute n = 18 into the nth term