1. Let's start by stating the problem clearly: you want to understand the solution to part d. 2. Since the exact problem statement for part d is not provided, I'll explain a general approach to solving typical part d questions in math problems, which often involve applying a formula or concept from previous parts. 3. Usually, part d requires using a formula such as $$y = mx + b$$ for linear equations, or applying a derivative, integral, or substitution depending on the context. 4. Important rules to remember: always identify what is given, what is asked, and which formulas or theorems apply. 5. For example, if part d asks to find the value of a function at a certain point, substitute the value into the function and simplify. 6. If it involves solving an equation, isolate the variable step-by-step, performing inverse operations carefully. 7. If you provide the exact problem statement or part d details, I can give a precise step-by-step solution. 8. Please share the full text of part d for a detailed explanation tailored to your problem.