Question

What is the sum of a 17–term arithmetic sequence where the first term is 9 and the last term is –87?

–718

–739

–663

–644

Answer 1

What is the sum of a 17–term arithmetic sequence
where the first term is 9 and the last term is –87?
Difference = 96/17
5< D < 6
9 + 4 + (-1) + (-6) + ...... +(-71)-----> -527
9 + 3 + (-3) + (-9) + ...... +(-87)------) -663

–663