1. Let's clarify the subtracting step you mentioned in step 3. 2. When subtracting expressions, remember to distribute the minus sign (or subtraction) to every term inside the parentheses. 3. For example, if you have $a - (b + c)$, it becomes $a - b - c$ after distributing the minus. 4. This is because subtracting a group is the same as subtracting each term individually. 5. If you provide the exact expressions from step 3, I can show you the detailed subtraction process. 6. Understanding this rule helps avoid mistakes in simplifying algebraic expressions.