Register
Identify the 42nd term of an arithmetic sequence where a1 = -12 and a27 = 66
138k views
1 vote
Identify the 42nd term of an arithmetic sequence where a1 = -12 and a27 = 66

User Donna
by
6.8k points

1 Answer

7 votes
a1 = -12
a2 = a1+d = -12+d
a3 = a2+d = a1+2*d = -12+2*d
.......
a27 = a26+d = a1+26*d = -12+26*d = 66

so: 26*d=66+12
26*d=78
d=78:26
d=3

therefore: a42 = a1+41*d = -12+41*3 = -12+123=111
User Inyoka
by
7.8k points
Ask a Question
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

7.5m questions

10.1m answers

Other Questions

How do you can you solve this problem 37 + y = 87; y =
How do you estimate of 4 5/8 X 1/3
Write words to match the expression. 24- ( 6+3)
A dealer sells a certain type of chair and a table for $40. He also sells the same sort of table and a desk for $83 or a chair and a desk for $77. Find the price of a chair, table, and of a desk.
The cost of 5 similar digital cameras and 3 similar video cameras is 3213. Each video camera costs 4 times as much as each digital camera. John buys a digital camera and a video camera. How much does he
Link Copied!