b. \( 4(12+9)= \)

Let’s break it down! First, you’re adding \(12\) and \(9\) inside the parentheses, which gives you \(21\). Then, you multiply \(21\) by \(4\). So, \(4 \times 21 = 84\). The final answer is \(84\)! Now, here’s a fun fact: Did you know that the distributive property plays a key role in making these calculations easier? Instead of solving it in two steps, you could also think of it as \(4 \times 12 + 4 \times 9\), which would give you the same result but can be handy for mental math or larger numbers!