In an arithmetic sequence and . What is the sum of the first 10 terms?
Answer and explanation
Correct answer: C.
- Step 1: From we get , and then . Step 2. . **Answer: . Why not the others:** takes by subtracting only once, is the sum of nine terms, and is only the tenth term.
Practise more Algebra, Functions, Geometry and Probability.
Free questions with an explanation for every one, and full timed Državna Matura (Montenegro) mock tests.