21q - 7p and (3q - p)(7)
1 answer:
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<h3>Answer: 39</h3>
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Explanation:
You can use the nCr formula shown below
where n = 39 and r = 1. However, you could also use the identity
which basically says there are n ways to pick 1 item if you are given a choice of n items. In this specific case, we have 39 items total, and there are 39 ways to pick one item.