What is the sum of the geometric series?

Answer:
40
Step-by-step explanation:
The given geometric series is:
[tex]\sum_{n=1}^4(-2)(-3)^{n-1}[/tex].
When n=1, [tex]a_1=(-2)(-3)^{1-1}[/tex], [tex]\implies a_1=(-2)(-3)^{0}=-2[/tex]
When n=2, [tex]a_2=(-2)(-3)^{2-1}[/tex], [tex]\implies a_2=(-2)(-3)^{1}=6[/tex]
When n=3, [tex]a_3=(-2)(-3)^{3-1}[/tex], [tex]\implies a_3=(-2)(-3)^{2}=-18[/tex]
When n=4, [tex]a_4=(-2)(-3)^{4-1}[/tex], [tex]\implies a_4=(-2)(-3)^{3}=54[/tex]
The sum of the given series is:
-2+6-18+54=40