what is the lowest common multiple for 5, 7, & 9?

315

lowest common multiple is the smallest number that each of 5,7,9 divides into evenly.

The best way to figure lcm's out is to factor each number first into prime numbers.

5 and 7 are prime, so there are no other factors with these.

9 = 3*3

So the lcm must include one 5, one 7 and two 3's, or

3*3*5*7 = 315

Here's another one: whats the lcm of 6, 8, 10?

Break each into prime factors:

6 = 2*3

8 = 2*2*2

10 = 2*5

So the lcm must include the largest number of each prime that occur in any one number, therefore,

it must include 3 2's, one 3 and one 5.

2*2*2*3*5 = 120 is the smallest number that 6,8, and 10 divide into evenly.

Lowest common multiple of 5,7 and 9 is the number which can be divided by all (5,7,9) to give a whole number (not fraction).

The lowest common multiple can be calculated by many methods. You can divide the numbers into multiples of prime numbers

5 = 5 * 1

7 = 7 * 1

9 = 3 * 3 * 1

Then multiply all the numbers keeping in mind that the common numbers need to be multiplied only once.

Hence, 5 * 7 * 3 * 3 * 1 = 315.

315

no common factors therefore LCM=5*7*9=315

315