The nth term of the geometric sequence is:
an=ar^(n-1)
where
a=first term
r=common ratio
n=nth term
from the question:
120=ar(3-1)
120=ar^2
a=120/(r^2)....i
also:
76.8=ar^(5-1)
76.8=ar^4
a=76.8/r^4.....i
thus from i and ii
120/r^2=76.8/r^4
from above we can have:
120=76.8/r²
120r²=76.8
r²=76.8/120
r²=0.64
r=√0.64
r=0.8
hence:
a=120/(0.64)=187.5
therefore the formula for the series will be:
an=187.5r^0.8
5,280feet (1.609km) hope this help if u have another question feel free to ask :)
Answer:
There is no picture
Step-by-step explanation:
It's b)
you can test it by multiplying 6 by 4
X = (1/2)y + 6
x + y = 21
Substitute (1/2)y + 6 as x into the equation x + y = 21 since x = (1/2)y + 6.
[(1/2)y + 6] + y = 21
0.5y + 6 + y = 21
1.5y = 15
y = 10
Same thing, now substitute 10 as y in the other equation.
x + y = 21
x + (10) = 21
x = 11
