SOLUTION: state three consecutive terms in the arithmetic progression 40,33,26 ...which sum up to 15

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Question 830646: state three consecutive terms in the arithmetic progression 40,33,26 ...which sum up to 15
Answer by reviewermath(1029) About Me  (Show Source):
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Q:
State three consecutive terms in the arithmetic progression 40,33,26 ...which sum up to 15.
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A:
The common difference is equal to
33 - 40 = 26 - 33 = -7
The three consecutive terms are x, x - 7, and x - 14.
x + (x - 7) + (x - 14) = 15
3x - 21 = 15
x = (15 + 21)/3 = 12
x - 7 = 5 and
x - 14 = -2
Three consecutive terms: 12, 5, -2