Question

PLEASE HELP I HAVE ONLY TILL 11:59 TO GET THESE QUESTIONS DONE.

What is the common difference of a 57-term arithmetic sequence where the first term is -25 and the sum is 17,727? (1 points)
Answer

11

11.5

12

12.5


What is the sum of a 14-term arithmetic sequence where the last term is 30 and the common difference is -5? (1 points)
Answer

875

812.5

455

422.5

Answer 1

12

Answer 2

Use the formulas for the sum (S) and last term (l)
S = n[2a+(n-1)d]/2
l = a + (n-1)d
where a=first term, n=number of terms, d=common difference