The sum if the geometric sequence given by:
an=-2(3)^(n-1)
will be:
when:
n=1
an=-2
when n=2
a2=-6
when n=3
a3=-18
when n=4
a4=-54
when n=5
a5=-162
when n=6
a6=-486
when n=7
a7=-1458
when n=8
a8=-4374
thus the summation of the term will be:
Sn=(-4374+-1458+-486+-162+-54+-18+-6+-2)
Sn=-6560
the answer is -6560
Given:
Joining fee = $28
Fee of each event = $4
To find:
Total cost for someone to attend 4 events.
Solution:
Let the number of events be x and total fee be y.
Fee for 1 event = $4
Fee for x events = $4x
Joining fee remains constant. So, the total fee is

Substitute x=4 in this equation.



Therefore, total cost of 4 events is $44.
1047.84ft² is not covered by the pool.
Find the area of the yard covered by pull using the area of a circle formula (the height is irrelevant in this case). If the diameter of the pool is 24 feet, its radius is 12 (half of the diameter)
A = 3.14r^2
A =3.14(144)
A = 452.16 ft²
Subtract the area of the pool from the area of the yard to get the area of the yard that is not covered by the pool. If the dimensions of the yard are 30ft by 50ft, you multiply them to get the area: 1500ft²
Total yard area: 1,500ft²
Area of yard without pool: 1,500ft² - 452.16ft² = 1047.84ft²
Ratio is the comparison of sizes of two quantities of the same unit. Proportions are the equality of two ratios. A/b =c/d