The answer to this is 36.
The polynomial is the same in standard form
Sn=sum of the n terms of the geometric sequence.
a= the first term
r=the common ratio
n=numbers of terms.
Sn=a[(1-r^n)/(1-r)]
In this case:
a=-3
r=a₂/a₁=15/-3=-5
n=9
S₉=-3[(1-(-5)⁹) / (1-(-5))=
S₉=-3(1+1953125)/6)=
S₉=-3(1953126/6)=
S₉=-3(325521)
S₉=-976563
Answer: A. -976563
<h3><u>Question:</u></h3>
Isabella’s rain gauge showed 3 4/5 centimeters (cm) last Tuesday. This Tuesday, the rain gauge showed 5 7/10 centimeters. How many more centimeters of rain fell during the week?
A 9 1/2cm B 8 1/2cm c 2 4/5cm D 1 9/10 cm
<h3><u>Answer:</u></h3>
Option D
more centimeters of rain fell during this week than last week
<h3><u>Solution:</u></h3>
From given,

Also given that,

<em><u>How many more centimeters of rain fell during the week?</u></em>

Thus
more centimeters of rain fell during this week than last week