3 is the answer.
Solutions:
Odd Terms: 17, 18, 19, 20
Find the common difference.
d = a₂ - a₁
d = 18 - 17
d = 1
Thus, for every odd term, the next terms are derived by adding 1.
Even Terms: 9, 7, 5, x
Find the common difference.
d = a₂ - a₁
d= 7 - 9
d = -2
Find x.
x = 5 + d
x = 5 + (-2)
x = 5 - 2
x = 3
Therefore, x = 3.
What is a sequence?
In an arithmetic sequence, a term is obtained by adding a constant number to the preceding term. A sequence whose succeeding terms are obtained by adding a constant. Constant is called the common difference. Formula is a_n = a₁ + d(n - 1). The common difference is obtained by subtracting the first term from the second term.
Learn more about sequences are:https://brainly.com/question/6561461
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