$\"\"$

\

The expression is $\"\"$ .

\

Add the polynomials horizontally

\

$\"\"$ (Remove brackets)

\

$\"\"$ (Apply commutative property of addition: $\"\"$ )

\

$\"\"$ (Subtract: $\"\"$ )

\

$\"\"$ (Subtract: $\"\"$ ) $\"\"$

\

The sum of polynomials is $\"\"$ .