This question is from the book Abstract Algebra: Theory and Applications by Thomas W. Judson.
Chapter 2 – Question 4
Prove that
$$x + 4x + 7x + \cdots + (3n – 2)x = \frac{n(3n – 1)x}{2}$$ for $n \in \mathbb{N}$.
This question is from the book Abstract Algebra: Theory and Applications by Thomas W. Judson.
Prove that
$$x + 4x + 7x + \cdots + (3n – 2)x = \frac{n(3n – 1)x}{2}$$ for $n \in \mathbb{N}$.