C is the answer for this question
Answer:
4
Step-by-step explanation:
Answer:

Try to solve the similtanious equation to find the first term and the common difference, then use that information to figure out the 80th term... Update me if you need further help ...
Scientific notation means the numbers have to be between 1 and 10, so here is the answer as well as where to move the decimal
Answer: 87/13
Step-by-step explanation: You take you 5 and times it by 13 and + 9 because the equation is saying 13/13 5 times plus the 9/13,
So 6*13 = 78 78+9=87 and then you take the 87 and put it over the 13,
So, now you have your answer: 87/13