Ineed

what is the least common multiple of 4 and 10?

2

20

40

100

LCM (least common multiple)

The multiples of 4 is: 2 x 2
The multiples of 10 is: 2 x 5

In GCF, you multiply the common factors ONLY, but for the LCM, you need to multiply ALL the numbers.

The number 2 has a pair intersecting the multiples of 4 and 10, so you need to write it down only once, but the other 2 doesn't have a pair, so you should write it down.
So 2 x2 x 5
4x5=20

Hope this helped!