Question

What is the LCM of 5 and 9?

Answer 1

It is `45`. See explanation.

Explanation:

The lowest common multiple (LCM) of numbers `a` and `b` can be calculated as:

`lcm(a,b)=(axxb)/gcd(a,b)`

where `gcd` is the greatedt common divisor

In the given example the greatest common divisor (gcd) is `1`, so the lowest common multiple is `lcm(5,9)=5xx9=45`

Answer 2

`"LCM(5,9)=45"`

Explanation:

Multiples of `5:{5,10,15,20,25,30,35,40,color(red)45,50,55,60,...}`

Multpiles of `9:{9,18,27,36,color(red)45,54,63,72,....}`

From the lists we see that 45 is the [least common multiple].(https://socratic.org/prealgebra/factors-and-multiples/least-common-multiple)

`"LCM(5,9)=45"`