Sum of First N Multiples of M
Review the Lesson | MATHguide homepage Updated July 3rd, 2019


Status: Waiting for your answers.


Problem:Find the sum of the first 135 multiples of 5.

Plan:
  1. Find the first three terms and last term of the series.
  2. Use the sum formula to calculate the sum of the series, S135.
Step 1:
a1 + a2 + a3 + ··· + an
+ + + ··· +


Step 2:S135 =