Find the least common denominator (LCD) of the list of expressions: \(\frac{1}{x^2-4}, \frac{1}{x^2-1}, \frac{1}{x^2-9}\)

Step 1 ：Step 1: Factorize the denominators: \(x^2-4 = (x-2)(x+2)\), \(x^2-1 = (x-1)(x+1)\), \(x^2-9 = (x-3)(x+3)\)

Step 2 ：Step 2: Identify the unique factors: (x-2), (x+2), (x-1), (x+1), (x-3), (x+3)

Step 3 ：Step 3: Multiply all the unique factors to find the LCD: \((x-2)(x+2)(x-1)(x+1)(x-3)(x+3)\)