2-1

Do you mean 2 − 1 = 1? If you’re referring to a specific problem labeled “2-1” (like Chapter 2, Problem 1) please paste the exact question or tell me the course/topic (e.g., Calculus I, Linear Algebra, Statistics). I’ll walk you through a solution step by step.

If you just want quick practice, I can generate a few 2-1 style problems for common topics. Which subject and level are you studying?