4. \( 7(2+6-4 d) \)

Let’s simplify this expression together! First, you need to distribute the \( 7 \) across the terms inside the parentheses. So, calculate \( 2 + 6 - 4d \), which simplifies to \( 8 - 4d \). Next, you multiply everything by \( 7 \): \[ 7 \times (8 - 4d) = 56 - 28d \] And there you have it! The simplified expression is \( 56 - 28d \). Now, here's a fun thought: did you know that distributing (like what we just did) is a fundamental concept in algebra that dates back to ancient civilizations? The Babylonians had their own methods of solving polynomial equations long before modern notation was established. It’s fascinating how these principles have stood the test of time! For those diving deeper into algebra, there are many resources available. Consider classic textbooks like "Algebra for Dummies" or online platforms like Khan Academy. They break down concepts in a digestible way, which makes learning enjoyable and interactive! Plus, practicing problems keeps your mind sharp and ready for even trickier equations down the road!