15) \( \sqrt{3} \cdot \sqrt{3} \)

When you multiply \( \sqrt{3} \cdot \sqrt{3} \), it’s like inviting a friend to join you for a fun math party! Since the square root and the square just love to cancel each other out, this means you end up with \( 3 \). So, the excitement of the calculation gives you a nice, neat answer: \( 3 \). If you’re ever stuck on square roots, think of them as the ultimate "undo" button! Just like checking if you forgot to add something to your math bag, the square root of a number multiplied by itself gives you the original number back. So remember, \( \sqrt{x} \cdot \sqrt{x} = x \) always holds true in the realm of numbers!