Question

How to find the $LCM$ of $7$ and $9$?

Answer 1

Step 1: Explain how to find LCM of two numbers

The Least Common factor can be calculated in two ways; with the $LCM$ formula calculation of Highest Common Factor $(H.C.F)$, or multiplying the prime factors with the highest exponent factor.

Step 2: Find the $LCM$

Prime factors of $7$ is

$7=1\times 7$

Prime factors of $9$ is

$9=3\times 3$

$$\begin{gathered} HCF(7,9)=1 \\ LCM(7,9)=\frac{7\times 9}{1} \\ =\frac{63}{1} \\ =63 \end{gathered}$$

Hence, the $LCM$ of $7$ and $9$ is $63$.