For the arithmetic sequence beginning with the terms {11, 17, 23, 29, 35 ...}, what is the sum of the first 17 terms?

Me with this one question, and i'll upvote the brainliest answer

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

Find the midpoint m of z1=(8+5i) and z2=(12+3i)