We learned about sequences.

A Sequence is a set of things that are in order. And, each number in the sequence is called a term.

We have two sequences, Arithmetic sequences and Geo metric sequences.

・Arithmetic sequences

In an Arithmetic Sequence the difference (Which can write “d”) between one term and the next is a constant.

For this example, we need to add 2 constantly.

＊How to solve

Most important thing is rules. So, when we solve this question we need just find rules.

For example, if I have, “10 12 14 16 18…… “ the rules is “t(n) = 2X +8”.

First number of this sequences is 10, and differences are 2.

And, First number doesn’t have differences, so we need not to count first one.

Which mean correctly rules is “t(n) = 2(n-1)+10”

And, If we simplify this one It gonna be “t(n) = 2n-2+10 → t(n) 2n+8”