Find the LCM 21x^2 , 7x^2+14x

Since ${\displaystyle 21x^2,7x(x+2)}$ contain both numbers and variables, there are four steps to find the LCM. Find LCM for the numeric, variable, and compound variable parts. Then, multiply them all together.

Steps to find the LCM for ${\displaystyle 21x^2,7x(x+2)}$ are:

1. Find the LCM for the numeric part ${\displaystyle 21,7}$.

2. Find the LCM for the variable part ${\displaystyle x^2,x^1}$.

3. Find the LCM for the compound variable part ${\displaystyle x+2}$.

4. Multiply each LCM together.

The LCM is the smallest positive number that all of the numbers divide into evenly.

1. List the prime factors of each number.

2. Multiply each factor the greatest number of times it occurs in either number.

${\displaystyle 21}$ has factors of ${\displaystyle 3}$ and ${\displaystyle 7}$.

Since ${\displaystyle 7}$ has no factors besides ${\displaystyle 1}$ and ${\displaystyle 7}$.

${\displaystyle 7}$ is a prime number

The LCM of ${\displaystyle 21,7}$ is the result of multiplying all prime factors the greatest number of times they occur in either number.

Multiply ${\displaystyle 3}$ by ${\displaystyle 7}$.

The factors for ${\displaystyle x^2}$ are ${\displaystyle x\cdot x}$, which is ${\displaystyle x}$ multiplied by each other ${\displaystyle 2}$ times.

${\displaystyle x}$ occurs ${\displaystyle 2}$ times.

The factor for ${\displaystyle x^1}$ is ${\displaystyle x}$ itself.

${\displaystyle x}$ occurs ${\displaystyle 1}$ time.

The LCM of ${\displaystyle x^2,x^1}$ is the result of multiplying all prime factors the greatest number of times they occur in either term.

Multiply ${\displaystyle x}$ by ${\displaystyle x}$.

The factor for ${\displaystyle x+2}$ is ${\displaystyle x+2}$ itself.

${\displaystyle (x+2)}$ occurs ${\displaystyle 1}$ time.

The LCM of ${\displaystyle x+2}$ is the result of multiplying all factors the greatest number of times they occur in either term.