$\"\"$

The polynomial is $\"\"$ .

Horizontal method:

Subtract $\"\"$ by adding its additive inverse.

$\"\"$ (The additive inverse of $\"\"$ is $\"\"$ ) $\"\"$ (Group like terms)

$\"\"$ (Apply additive inverse property: $\"\"$ )

$\"\"$ (Add: $\"\"$ )

$\"\"$ (Apply additive inverse property: $\"\"$ )

The value of $\"\"$ $\"\"$ . $\"\"$

Vertical method:

Align like terms in columns and subtract by adding the additive inverse.

$\"\"$

Thus, The value of $\"\"$ $\"\"$ . $\"\"$

The value of $\"\"$ $\"\"$ .