Question

What is the 23rd term of the arithmetic sequence where a1 = 6 and a5 = 20?

Answer 1

Can you define \( a_5\) in terms of \( a_1\) ?

Answer 2

a1=6 first term
for an Airthmetic Sequence
nth term is given as
an=a1+(n-1)*d
where d is the common difference
a1=6
a5=20
using a5 and a1 we can find d
then use the nth term formula to find a23

Answer 3

so do you agree that a5 = 6 +4d, therefore, it can be concluded that 6+4d =20 since a5 =20, therefore d = 7/2
To find a23 we now simply just sub in the no.s into the equation
an=a1+(n-1)*d
a23 =6+ (23-1)* 7/2
=83