What is the Least Common Multiple of 18 and 38?
Least common multiple or lowest common denominator (lcd) can be calculated in two way; with the LCM formula calculation of greatest common factor (GCF), or multiplying the prime factors with the highest exponent factor.
Least common multiple (LCM) of 18 and 38 is 342.
LCM(18,38) = 342
Least Common Multiple of 18 and 38 with GCF Formula
The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 18 and 38, than apply into the LCM equation.
GCF(18,38) = 2
LCM(18,38) = ( 18 × 38) / 2
LCM(18,38) = 684 / 2
LCM(18,38) = 342
Least Common Multiple (LCM) of 18 and 38 with Primes
Least common multiple can be found by multiplying the highest exponent prime factors of 18 and 38. First we will calculate the prime factors of 18 and 38.
Prime Factorization of 18
Prime factors of 18 are 2, 3. Prime factorization of 18 in exponential form is:
18 = 21 × 32
Prime Factorization of 38
Prime factors of 38 are 2, 19. Prime factorization of 38 in exponential form is:
38 = 21 × 191
Now multiplying the highest exponent prime factors to calculate the LCM of 18 and 38.
LCM(18,38) = 21 × 32 × 191
LCM(18,38) = 342