standard_description: Use addition to find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns; write an equation to express the total as a sum of equal addends.
problem_activity: Are the following two expressions equivalent? Explain your reasoning using the properties of operations. Provide examples to support your reasoning.
Expression 1:
$${(x-y)-z }$$
Expression 2:
$${x-(y-z)}$$


aligns: no