The first four terms of an arithmetic sequence are given below.
Choose the algebraic expression that represents the nth
term in this sequence.
7, -3, -13, -23, . . .
7n - 10
-10n + 17
-10n + 7
10n
10n + 17
2
The expression you selected, -10n + 17, is correct. Good job!
The student answered this item correctly. This item involves recognizing the explicit formula that correctly describes the "nth term" of a sequence. The fact that this sequence is decreasing contributes to this item's difficulty.
1
The expression you selected, 7n - 10, is incorrect. The sequence in the question is: 7, -3, -13, -23,. . . The expression you selected describes the sequence: -3, 4, 11, 18,. . .
The student answered this item incorrectly. This item involves recognizing the explicit formula that correctly describes the "nth term" of a sequence. The fact that this sequence is decreasing contributes to this item's difficulty.
3
The expression you selected, -10n + 7, is incorrect. The sequence in the question is: 7, -3, -13, -23,. . . The expression you selected describes the sequence: -3, -13, -23, -33,. . .
The student answered this item incorrectly. This item involves recognizing the explicit formula that correctly describes the "nth term" of a sequence. The fact that this sequence is decreasing contributes to this item's difficulty.
4
The expression you selected, 10n, is incorrect. The sequence in the question is: 7, -3, -13, -23,. . . The expression you selected describes the sequence: 10, 20, 30, 40,. . .
The student answered this item incorrectly. This item involves recognizing the explicit formula that correctly describes the "nth term" of a sequence. The fact that this sequence is decreasing contributes to this item's difficulty.
5
You have the right idea, but the expression you selected, 10n + 17, is incorrect. Hint: it looks like you may have dropped a sign. The sequence you in the question is: 7, -3, -13, -23,. . . The expression you selected describes the sequence: 27, 37, 47, 57,. . .
The student answered this item incorrectly. This item involves recognizing the explicit formula that correctly describes the "nth term" of a sequence. The fact that this sequence is decreasing contributes to this item's difficulty.
ExplicitArithmetic