Question

A8=21 a10=27 find nth term arthemetic sequence

Answer 1

Answer:

an = 3n - 3

Step-by-step explanation:

The nth term of an arithmetic progression is expressed as;

an = a + (n-1)d

a is the first term

n is the number of terms

d is the common difference

a8 = a + (8-1)d

a8 = a + 7d = 21 ....1

a10 = a+9d = 27 ....2

Subtract 1 from 2

7d  - 9d = 21 - 27

-2d = -6

d = -6/-2

d = 3

Since a + 7d = 21

a + 7(3) = 31

a + 21 = 21

a = 21 - 21

a = 0

Get the nth term

Recall that an = a + (n-1)d

an = 0 + (n-1)*3

an = 3n - 3

Hence the nth term of the sequence is 3n - 3