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
Answer:
Step-by-step explanation:
5:2:3....added = 10
5/10(25) = 125/10 = 12.5 liters of pear juice
2/10(25) = 50/10 = 5 liters pineapple juice
3/10(25) = 75/10 = 7.5 liters plum juice
Answer: 30
Step-by-step explanation: