How many of these sequences have a common different of -4? -19, -15, -11, -7, -3, ... 19, 15, 11, 7, 3, ... 3, 7, 11, 15, 19, ... -3, 7, -11, 15, -19, ... 0 1 2 3
Mathematics · High School · Tue Nov 03 2020
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Determine the number of sequences that have a common difference of -4.
-19, -15, -11, -7, -3, ...
19, 15, 11, 7, 3, ...
3, 7, 11, 15, 19, ...
-3, 7, -11, 15, -19, ...
0, 1, 2, 3, …
In order to determine the common difference of each sequence, we subtract the second term by the first term.
-19, -15, -11, -7, -3, ...
Common Difference = -15 - (-19)
Common Difference = 4
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19, 15, 11, 7, 3, ...
Common Difference = 15 - 19
Common Difference = -4
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3, 7, 11, 15, 19, ...
Common Difference = 7 - 3
Common Difference = 4
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-3, 7, -11, 15, -19, ...
The given sequence has a common ratio, not a common difference.
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0, 1, 2, 3, …
Common Difference = 2 - 1
Common Difference = 1
Only 1 sequence has a common difference of -4, and that sequence is 19, 15, 11, 7, 3, ...