Write a function `divide(a, b, callback)` that divides a by b and calls callback in Node.js error-first style: `callback(error, result)`. If b is 0, pass an Error.

💡 Hint 1: Error-first callbacks have the signature: callback(err, result). 💡 Hint 2: If no error, pass null as the first argument. 💡 Hint 3: if (b === 0) callback(new Error("Division by zero")); else callback(null, a / b); ✅ Solution: ```javascript function divide(a, b, callback) { if (b === 0) { callback(new Error("Division by zero")); } else { callback(null, a / b); } } ```