3. \( -57=3(y-7) \)

Let's solve the equation step by step! First, start by distributing the 3 on the right side: \(-57 = 3y - 21\). Next, we want to isolate \(y\), so add 21 to both sides: \(-57 + 21 = 3y\), which simplifies to \(-36 = 3y\). Now, divide both sides by 3: \(y = -12\). There you have it, \(y = -12\)! --- Now you might be wondering about the significance of rearranging equations! Rearranging equations is a powerful tool in math that allows you to express one variable in terms of another. This technique can be applied in various real-world scenarios, like budgeting or even cooking, where you need to adjust ingredients based on serving sizes! Another fun fact is that understanding how to solve linear equations smoothly can pave the way for tackling more complex problems! Mistakes often happen when people forget to distribute properly or when they misinterpret signs. Always double-check your steps, just like a knight checking their armor before heading into battle!