Question

An arithmetic sequence has a1 = 22 and a8 = 43. Find a15.

Answer 1

The 15th term of the arithmetic sequence $a_{15} = 64$

Option B is correct

The nth term of an arithmetic sequence is given as:

$a_{n} = a + (n - 1)d$

The first value, a = 22

$a_8 = a+(8 - 1)d\\a_8 = a + 7d$

Since $a_8 = 43$

$43 = 22 + 7d\\7d = 43 - 22\\7d = 21\\d = \frac{21}{7}\\d = 3$

The common difference, d = 3

$a_{15}= a + (15-1)d\\a_{15} = a + 14d\\a_{15} = 22 + 14(3)\\a_{15} = 22 + 42\\a_{15} = 64$

The 15th term of the arithmetic sequence = 64

Learn more here: brainly.com/question/24072079