What is the sum of a 30–term arithmetic sequence where the first term is 74 and the last term is –100?

Question

callisto · Answer

probably you can use the formula sum of terms = (a+l)*n/2
where a = first term
          l = last term
          n = number of terms
i think you've got all the unknowns what you need to do is to substitute the numbers into the formula and get the answer

amistre64 · Answer

posting multiple question on the same topic without interacting with those who are trying to help is a red flag.  it indicates that you might simply be posting your homework/test questions to get answers only and not as a means of studying the material to learn.

so please feel free to interact with others in the site.

lgbasallote · Answer

sn = n(a1 + an)/2

a30 = -100
a1 = 74

s30 = 30(74 -100)/2
s30 = 30(26)/2
s30 = 390

anonymous · Answer

I didm't read the question properly, my apologies.

$$15 \times (74-100) = ? $$