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# Find the first 5 terms of the series whose $n^{th}$ term is $a_n=n(n+2)$

$\begin{array}{1 1}3,8,15,24,35 \\ 3,9,15,24,35 \\3,8,15,25,35 \\ 3,8,12,24,35 \end{array}$

Toolbox:
• If $n^{th}$ term is known, put $n=1,2,3......$ to get the series.
Given: $t_n=n(n+2)$
$\therefore\:t_1=1(1+2)=3$
$t_2=2(2+2)=8$
$t_3=3(3+2)=15$
$t_4=4(4+2)=24$
$t_5=5(5+2)=35$
$\therefore \:$ The first 5 terms of the series are
$3,8,15,24,35$