Find the 21st term of the sequence 15,8,1,-6
1 answer:
Answer:
-125
Step-by-step explanation:
Each term is 7 less than the previous term.
1st term: 15
2nd term: 15 - 7
3rd term: 15 - 7 - 7 = 15 - 2(7)
4th term = 15 - 7 - 7 - 7 = 15 - 3(7)
Notice that each term is 15 minus a multiple of 7. The multiple is obtained by multiplying 7 by 1 less than the term number.
The formula is:
For the 21st term, multiply 7 by 20, and subtract from 15.
7 × 20 = 140
15 - 140 = -125
Using the formula:
Answer: -125
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Answer:
The symphonic choir can record a maximum of 14 songs.
Step-by-step explanation:
We know that the album cannot be more than 72 minutes long, and the jazz choir records a total of song minutes.
If we call the number of songs the symphonic choir records , and each song is 3.5 minute long, then the song minutes for the symphonic choir are
; therefore, we have the inequality
<em> (this says the song minutes for jazz choir plus song minutes for symphonic choice cannot exceed 72 minutes )</em>
We solve this inequality by subtracting 21 from both sides and then dividing by 3.5:
The maximum integer value can take is 14; therefore, the maximum number of songs the symphonic choir can record is 14 songs.