consider an arithmetic sequence whose 7th term is 34 and 15th term is 66 find its common difference
Answers
Answer:
good morning ma'am I am a correct the problem is that the year
Step-by-step explanation:
follow please
Step-by-step explanation:
Consider an arithmetic sequence whose 7th term is 34 and the 15th terms are 66. What is the common difference and what is the 20th term?
Ad by Life Insurance Corporation
Savings and Security: Enjoy twin benefits with LIC's SIIP.
Invest your hard-earned money while also providing financial security for your family. Buy it online!
Learn More
3 Answers

Glen Melnik, Private Tutor (1981-present)
Answered 10 months ago · Author has 115 answers and 44.7K answer views
Consider an arithmetic sequence whose 7th term is 34 and the 15th terms are 66. What is the common difference and what is the 20th term?
To answer this question, we will build two equations with two unknowns, using
a(n) = a(1) + (n-1)d
so,
34 = a(1) + 6d
66 = a(1) +14d
Using elimination by multiply the first term by -1, we get:
-34 = -a(1) -6d
66 = a(1) + 14d
which becomes,
32 = 8d
d = 4
plugging that difference into the first equation, we get
34 = a(1) +6(4)
a(1) = 10
Since we know now know the difference and the first term, we use the first equation is get the 20th term.
a(20) = 10 + (20–1)4
a(20) = 86.
So, the answers to this problem are 4 for the difference, and 86 for the 20th terms.