$\"\"$

The expression is $\"\"$ .

Step 1:

Find one half of $\"\"$ ,the coefficient of $\"\"$ .

Find one half of $\"\"$ is $\"\"$ .

Step 2:

Square the result in Step 1.

$\"\"$ .

Step 3:

Add the result of step 2 to $\"\"$ .

$\"\"$ .

$\"\"$ .

The trinomial $\"\"$ can be written as $\"\"$ .

$\"\"$

$\"\"$ , The trinomial $\"\"$ is perfect square.