Answer: -3
Step-by-step explanation:
im doing this problem right now---
ok so a1=256 a2=64 a3=15 a4=4... find a9
the sequence divides by 1/4 every term
an=a1*r^n-1
an=(256)*(1/4)^n-1
replace n with 9
A9=(256)*(1/4)^9-1
A9=(256)*(1/4)^8
=(256)*(1/4)
A9=64^8
1/256 or a9= 0.00390625
Isabel can drive 505.85 miles with a gas tank that holds 15.1 gallons of gas
<em><u>Solution:</u></em>
Given that, Isabel’s car gets 33.5 miles per gallon
Her gas tank holds 15.1 gallons of gas
To find: Number of miles can Isabel drive on a full tank of gas
Let "x" be the miles drive with 15.1 gallons of gas
From given,
1 gallon = 33.5 miles
15.1 gallon = x miles
This forms a proportion and we can solve the sum by cross multiplying

Thus Isabel can drive 505.85 miles on a full tank of gas