Hope this helps the answer is 2 1/8 the picture explains how i did it :)
Answer:
53 1/3 km/h
Step-by-step explanation:
The car is going at 80km in 1.5 hours, so if you divide that value you get 26 2/3 km for every half hour, now you would want to multiply this times 2 to find the value for every hour, so then this would give you the answer 53 and 1/3 kilometers per hour.
For an explicit formula in its simplified form, we must evaluate the first two terms.
For

,

, and

. We see that the common difference is

, and

, so we write,

.
The correct answer is
B.