Answer
First three terms: $2,-1,-4$
last term: $-85$
Sum of the an arithmetic series: $-1245$
Work Step by Step
First three terms can be found as:$a_1=-3+5=2;a_2=-6+5=-1;a_3=-9+5=-4$
Last term can be found as: $a_{30}=-3(30)+5=-85$
Sum of the an arithmetic series can be calculated by using formula $S_n=\dfrac{n}{2}(a_1+a_n)$
Here $n=30$
Thus,
$S_{30}=\dfrac{30}{2}(2-85)=-1245$
our results are:
First three terms: $2,-1,-4$
last term: $-85$
Sum of the an arithmetic series: $-1245$
