# Week 1 – Arithmetic Sequence

Find $t_{50}$ $t_{n}$ $s_{50}$ 5, 9, 13, 17, 21

$t_{n}=t_1+(n-1)d$

$t_{n}=5+(n-1)4$

$t_{n}=5+4n-4$

$t_{n}=1+4n$

$t_{50}=1+4(50)$

$t_{50}=201$

$S_n=\frac{n}{2}(t_1+t_n)$

$S_{50}=\frac{50}{2}(5+201)$

$S_{50}=25(5+201)$

$S_{50}=25(206)$

$S_{50}=5150$

This week I learned about sequences and I learned how to use these formulas properly. Now with any sequence I can find the different values.