Precalculus Examples

$15$ and $25$

Step 1

Find the common factors for the numerical part:

$15, 25$

Step 2

The factors for $15$ are $1, 3, 5, 15$ .

Tap for more steps...

Step 2.1

The factors for $15$ are all numbers between $1$ and $15$ , which divide $15$ evenly.

Check numbers between $1$ and $15$

Step 2.2

Find the factor pairs of $15$ where $x \cdot y = 15$ .

$\begin{array}{c} x & y \\ 1 & 15 \\ 3 & 5 \end{array}$

Step 2.3

List the factors for $15$ .

$1, 3, 5, 15$

Step 3

The factors for $25$ are $1, 5, 25$ .

Tap for more steps...

Step 3.1

The factors for $25$ are all numbers between $1$ and $25$ , which divide $25$ evenly.

Check numbers between $1$ and $25$

Step 3.2

Find the factor pairs of $25$ where $x \cdot y = 25$ .

$\begin{array}{c} x & y \\ 1 & 25 \\ 5 & 5 \end{array}$

Step 3.3

List the factors for $25$ .

$1, 5, 25$

Step 4

List all the factors for $15, 25$ to find the common factors.

$15$ : $1, 3, 5, 15$

$25$ : $1, 5, 25$

Step 5

The common factors for $15, 25$ are $1, 5$ .

$1, 5$

Step 6

The GCF (HCF) of the numerical factors $1, 5$ is $5$ .

$5$