11th Grade Arithmetic and Geometric Sequences Worksheet — Level 1 — Practice Set 4 — Answers
Answer sheet with worked solutions for the 11th Grade sequences & series worksheet.
Success TutoringWorksheetsAnswer sheet11th Grade · Mathematics · Sequences & Series11th Grade Arithmetic and Geometric Sequences Worksheet — Level 1 — Practice Set 4 — Answers
Arithmetic: Tₙ = a + (n − 1)d. Geometric: Tₙ = arn − 1. Show your work.
1.Find the 15th term of the arithmetic sequence −8, −10, −12, −14, …
Answer: −36
- a = −8, d = −2
- T15 = −8 + 14 × −2 = −36
2.Find the 17th term of the arithmetic sequence 3, 10, 17, 24, …
Answer: 115
- a = 3, d = 7
- T17 = 3 + 16 × 7 = 115
3.Find the 22th term of the arithmetic sequence −1, 2, 5, 8, …
Answer: 62
- a = −1, d = 3
- T22 = −1 + 21 × 3 = 62
4.Find the 22th term of the arithmetic sequence 1, −4, −9, −14, …
Answer: −104
- a = 1, d = −5
- T22 = 1 + 21 × −5 = −104
5.Find the 25th term of the arithmetic sequence 13, 14, 15, 16, …
Answer: 37
- a = 13, d = 1
- T25 = 13 + 24 × 1 = 37
6.For the arithmetic sequence −8, −4, 0, 4, …, write the common difference and the rule for the nth term.
Answer: d = 4; Tₙ = 4n − 12
- d = −4 − (−8) = 4
- Tₙ = a + (n − 1)d = −8 + (n − 1) × 4 = 4n − 12
7.For the arithmetic sequence 4, 5, 6, 7, …, write the common difference and the rule for the nth term.
Answer: d = 1; Tₙ = n + 3
- d = 5 − 4 = 1
- Tₙ = a + (n − 1)d = 4 + (n − 1) × 1 = n + 3
8.Find the 18th term of the arithmetic sequence 9, 3, −3, −9, …
Answer: −93
- a = 9, d = −6
- T18 = 9 + 17 × −6 = −93
9.For the arithmetic sequence −2, −8, −14, −20, …, write the common difference and the rule for the nth term.
Answer: d = −6; Tₙ = −6n + 4
- d = −8 − (−2) = −6
- Tₙ = a + (n − 1)d = −2 + (n − 1) × −6 = −6n + 4
10.Find the 23th term of the arithmetic sequence 7, 12, 17, 22, …
Answer: 117
- a = 7, d = 5
- T23 = 7 + 22 × 5 = 117
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