Find the LCM 65 , 78

$65$ , $78$

Step 1

The LCM is the smallest positive number that all of the numbers divide into evenly.

1. List the prime factors of each number.

2. Multiply each factor the greatest number of times it occurs in either number.

Step 2

$65$ has factors of $5$ and $13$ .

$5 \cdot 13$

Step 3

The prime factors for $78$ are $2 \cdot 3 \cdot 13$ .

$78$ has factors of $2$ and $39$ .

$2 \cdot 39$

$39$ has factors of $3$ and $13$ .

$2 \cdot 3 \cdot 13$

Step 4

The LCM of $65, 78$ is the result of multiplying all prime factors the greatest number of times they occur in either number.

$2 \cdot 3 \cdot 5 \cdot 13$

Step 5

Multiply $2 \cdot 3 \cdot 5 \cdot 13$ .

Multiply $2$ by $3$ .

$6 \cdot 5 \cdot 13$

Multiply $6$ by $5$ .

$30 \cdot 13$

Multiply $30$ by $13$ .

$390$