### Examples

**Example 1:** Find the LCM of 4 and 10.

**Solution:**

Prime factorization of 4: 4 = 2, 2

Prime factorization of 10: 10 = 2, 5

Take the common factors once and remaining unique factors.

Multiply them together to get LCM.

Therefore, LCM(4, 10) = 20.
**Example 2:** Find the LCM of 24 and 15.

**Solution:**

Prime factorization of 24: 24 = 2, 2, 2, 3

Prime factorization of 15: 15 = 3, 5

Take the common factors once and remaining unique factors.

Multiply them together to get LCM.

Therefore, LCM(24, 15) = 120.
**Example 3:** Find the LCM of 3 and 7.

**Solution:**

Prime factorization of 3: 3 = 3

Prime factorization of 7: 7 = 7

Take the common factors once and remaining unique factors.

Multiply them together to get LCM.

Therefore, LCM(3, 7) = 21.

### Exercise

**1.** LCM(45,60) = 180

**2.** LCM(12,80) = 240

**3.** LCM(60,40) = 120

**4.** LCM(18,24) = 72

**5.** LCM(24, 36) = 72

**6.** LCM(12,80) = 240

**7.** LCM(72, 90) = 360

**8.** LCM(36, 45) = 180

**9.** LCM(84, 105) = 420

**10.** LCM(10,25) = 50