Arithmetic sequences add the same amount to each time. ex/ 7, 10, 13, 16…

Common difference stands for the amount increasing and is represented by (d). ex/ 7,10,13 d=3

Tn stands for the unknown number you’re trying to find, Tn could be the last number in the sequence or the 50th number.

T is used to represent the numbers in the sequence. ex/
7, 10, 13, 16…
T1,T2,T3,T4