What is the least common multiple of x and 3x?

The least common multiple (LCM) of two numbers is the smallest multiple that is divisible by both numbers. In this case, the LCM of x and 3x is the smallest multiple that can be divided evenly by both x and 3x. Since 3x is a multiple of x (3 times x), the LCM of x and 3x would simply be 3x.