$\"\"$

\

The expression is $\"\"$ .

\

$\"\"$ (Algebraic formula: $\"\"$ )

\

$\"\"$ (Multiply)

\

$\"\"$ (Substitute: $\"\"$ and $\"\"$ )

\

$\"\"$ (Addition: $\"\"$ )

\

$\"\"$ .

\

The simplified expression is $\"\"$ .

\

$\"\"$

\

$\"\"$ .