<P> The following formula reduces the problem of computing the least common multiple to the problem of computing the greatest common divisor (GCD), also known as the greatest common factor: </P> <Dl> <Dd> lcm ⁡ (a, b) = a ⋅ b gcd ⁡ (a, b). (\ displaystyle \ operatorname (lcm) (a, b) = (\ frac (a \ cdot b) (\ operatorname (gcd) (a, b))).) </Dd> </Dl> <Dd> lcm ⁡ (a, b) = a ⋅ b gcd ⁡ (a, b). (\ displaystyle \ operatorname (lcm) (a, b) = (\ frac (a \ cdot b) (\ operatorname (gcd) (a, b))).) </Dd> <P> This formula is also valid when exactly one of a and b is 0, since gcd (a, 0) = a . However, if both a and b are 0, this formula would cause division by zero; lcm (0, 0) = 0 is a special case . </P>

How many common factors are in 28 and 32