Answer:
20
Explanation:
To find the explicit equation for an arithmetic sequence, we can use the formula:
a_n = a_1 + d(n - 1)
where a_n is the n-th term of the sequence, a_1 is the first term of the sequence, and d is the common difference. Plugging in the values for this sequence, we get:
a_n = 100 + (-20)(n - 1)
Simplifying, we get:
a_n = 120 - 20n
This is the explicit equation for the sequence 100, 80, 60, 40, … You can use this equation to find any term of the sequence by plugging in the value of n. For example, to find the fifth term of the sequence, you can plug in n = 5 and get:
a_5 = 120 - 20(5) = 120 - 100 = 20