00:01
We're being asked to find the least common multiple between 42, 56, and 80 by using prime factorization.
00:06
So i have to write each of them as a product of their primes.
00:09
So let's start with 42.
00:10
I'm going to use a factor tree.
00:12
Well, 7 times 6 is 42 and 7's prime.
00:15
And 6 is 2 times 3, where 2 and 3 are prime.
00:18
So we can rewrite 42 as 2 times 3 times 7.
00:24
Now for 56, i know 7 times 8 is 56, 7's prime.
00:29
2 times 4 is 8, 2 is 8.
00:31
Is prime, and 2 times 2 is 4, where 2 is prime.
00:35
So we can rewrite 56 as 2 times 2 times 2 times 7.
00:41
And now for 80.
00:42
Well, i know that 10 times 8 is 80, and we can rewrite 10 as 2 times 5, where both of those are prime, and 8 is 4 times 2, where 4 is 2 times 2, and again, 2 is prime...