LCM for 19 and 42

798 is divisible by both: 798 ÷ 19 = 42, 798 ÷ 42 = 19 — and 42 and 19 share no factor but 1, so no smaller number is. As a common denominator: multiply the top and bottom of x/19 by 42 and of y/42 by 19.

19 and 42 are coprime (GCF = 1), so their LCM is simply the product: 19 × 42 = 798.

— = power 0: the prime is not a factor of this number; the LCM takes it from the number that has it.

LCM = 2 × 3 × 7 × 19 = 798