September 12, 2017 – Molly's Blog

My Arithmetic Sequence

mollys2015 on September 12, 2017

$3,6,9,12,15$ …

$t{n}=t{1}+(n-1)(d)$

$t_{50}=3+(50-1)(3)$

$t_{50}=3+147$

$t_{50}=150$

$t_{n}=3+(n-1)(3)$

$t_{n}=3+3n-3$

$t_{n}=3n$

$S_{n}=\frac{n}{2}(2(t_{1})+(n-1)(d))$

$S_{50}=\frac{50}{2}(2(3)+(50-1)(3))$

$S_{50}=25(6+147)$

$S_{50}=25(153)$

$S_{50}=3825$