1. The problem asks to solve number 2-4 parts a and b. Since the exact problem statement is not provided, I will assume it refers to solving two algebraic expressions or equations labeled 2-4 a and b. 2. For part a, let's assume the problem is to simplify or solve an expression or equation. The general approach is to identify the type of problem (e.g., linear equation, quadratic, factorization) and apply the relevant formula or method. 3. For part b, similarly, we apply the appropriate algebraic rules or formulas. Since the exact problems are not specified, please provide the exact expressions or equations for parts a and b of number 2-4 to proceed with detailed steps and solutions.