Expression 1
For this expression the commutative property applies, it allows you to rearrange the terms of the expression and still reach the same resullt.
Expression 2
For this expression the combining like terms property applies, to simplify the expresion you have to arrange all terms containing the same variable together in one group, and those who have not variable (constants) in other group
Expression 3
For this expression you have a term in parentheses that is being multiplied by 2, to solve this term you have to apply the distributive property of multilications