1. The problem is to continue the expression or equation for the term involving $4d$. 2. Without additional context, we assume the task is to simplify or express terms involving $4d$. 3. If the expression is linear, $4d$ remains as is. 4. If part of a polynomial or equation, identify the operation involving $4d$ (e.g., addition, multiplication). 5. For example, if the expression is $3 + 4d$, it remains $3 + 4d$. 6. If the expression is $4d \times 2$, then multiply to get $8d$. 7. If the expression is $4d + 5d$, combine like terms to get $9d$. 8. Without more details, the continuation for $4d$ depends on the operation or context. 9. Please provide the full expression or equation for precise continuation or simplification.