$\"\"$

The given expression is $\"\"$ .

Method 1: Horizontally addition

$\"\"$

$\"\"$ (Group the like terms)

Combine like terms using distributive property: ac + bc = (a + b)c.

$\"\"$

Method 2: Vertically addition

The given terms are in descending order and like terms are aligned.

$\"\"$

The solution is $\"\"$ .