Which best describes the relationship between the successive terms in the sequence shown? 9 comma negative 1 comma negative 11 comma negative 21 comma dots

Compare consecutive terms by subtraction: −1 − 9 = −10, −11 − (−1) = −10, and −21 − (−11) = −10. Because the same amount is added each time, the sequence has a common difference of −10, so the correct choice is “The common difference is negative 10.”

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