2-1

I’m not sure what “2-1” refers to. Do you mean: - the arithmetic 2 − 1, which equals 1, or - problem 2.1 from a textbook (chapter 2, section 1), or - something else (e.g., Section 2.1 in a particular course like calculus, linear algebra, probability, etc.)? If you can share the exact problem statement or the course/title, I’ll walk you through a step-by-step solution. In the meantime, here’s a quick generic approach for Section/Problem 2.1-type tasks: - Identify what is known and what must be found. - Choose an appropriate method (algebra, calculus, linear algebra, probability, etc.). - Write out steps clearly, citing definitions/theorems as needed. - Check your answer for consistency with the problem’s conditions. If you just want the plain arithmetic, 2 − 1 = 1. Let me know the context and I’ll tailor the help.