Question

What is the sum of a 22–term arithmetic sequence where the first term is 55 and the last term is –29?
please helpp

Answer 1

sum of n terms = (n/2)[ a + l]
where n = number of terms, a = first term and l = last term

Answer 2

so plug in your values to get
sum of 22 terms = (22/2)[ 55 - 29]

Answer 3

i got 286, i keep forgetting the different formulas

Answer 4

286 is correct