7. \( \left(8^{2}-7 \cdot 9\right) \)

First, let's break it down! Here, you'll want to handle the exponent first. \(8^2 = 64\). Now, move on to the multiplication: \(7 \cdot 9 = 63\). Finally, subtract: \(64 - 63 = 1\). So, your answer is \(1\)! Remember, when you're working with expressions like this, always follow the order of operations (PEMDAS/BODMAS) to get to the right answer efficiently!