Mathematics for IGCSE & O level - Number (Section 3 - No. 1)

The prime factorization of 84 is 2 x 2 x 3 x 7. The prime factorization of 180 is 2 x 2 x 3 x 3 x 5. The LCM is 2^2 * 3^2 * 5 * 7 = 1260.