Answer:

Step-by-step explanation:
we are given
sequence is geometric
so, we can use nth term formula

we have


we have to find a9
so, we can plug n=9
we get



Answer:
It will take at least 15 weeks
Step-by-step explanation:
12w+31 ≥ 205
Subtract 31 from each side
12w+31-31 ≥ 205-31
12w ≥ 174
Divide each side by 12
12w/12 ≥ 174/12
w ≥ 14.5
Rounding up to the nearest integer
w ≥ 15
It will take at least 15 weeks
989.75060139
100.023424234 divided by 10.32342 = 9.68898138737
9.68898138737 + 1000.293920 = 1009.98290139
1009.98290139 - 20.2323 = 989.75060139

This gives us

We can take 4x from each term to get

as your answer