Answer:
The right answer is:
Option OB: f(1) = -9
Common difference: 7
Step-by-step explanation:
Given sequence is:
-9, -2, 5, 12,...
Here the first number is f(1)
Common Difference:
Common difference is the difference between consecutive terms of an arithmetic sequence. It is denoted by d.
In the given sequence,
f(1) = -9
f(2) = -2
f(3) = 5
Hence,
The right answer is:
Option OB: f(1) = -9
Common difference: 7
When you say "at the same ratio", you mean that you consume the same amount of gas for the same amount of miles.
We know that everytime you drive 75 miles, you use 3 gallons of gas.
Since 12 gallons of gas is four times 3 gallons of gas, if the ratio remains the same, you can drive four times the distance:
You drive 75 miles, and use 3 gallons.
You drive 75 more miles (so you are at miles) and use 3 more gallons, so you use
gallons.
You drive 75 more miles (so you are at miles) and use 3 more gallons, so you use
gallons.
You drive 75 more miles (so you are at miles) and use 3 more gallons, so you use
gallons, and you're done.