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Find the 20th term of the arithmetic sequence whose common difference is d=-4 and whose first term is a1 = 3 .

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To find the 20th term of an arithmetic sequence, we can use the formula:

an = a1 + (n - 1)d

where:
an is the nth term of the sequence,
a1 is the first term of the sequence,
n is the position of the term in the sequence,
and d is the common difference.

In this case, the first term (a1) is 3 and the common difference (d) is -4. We want to find the 20th term, so we substitute these values into the formula:

a20 = 3 + (20 - 1)(-4)

Simplifying the equation:

a20 = 3 + 19(-4)
a20 = 3 - 76
a20 = -73

Therefore, the 20th term of the arithmetic sequence is -73.
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