Answer
First five terms $5,-15,45,-135,405$
Work Step by Step
Given: $a_1=5 $ and $r=-3$
Formula for a Geometric sequence, so $a_n=5(-3)^{n-1}$
when n=2; $a_2=a_1r=5(-3)=-15$
when n=3 ; $a_3=a_2r=-15(-3)=45$
when n=4 ;$a_4=a_3r=45(-3)=-135$
when n= 5;$a_5=a_4r=-135(-3)=405$
Thus, First five terms $5,-15,45,-135,405$
