CPM Homework Help : CAAC Problem 2-69

Sylvia simplified the expressions on the expression comparison mat shown below. Some of her work is shown. Are all of her moves “legal”? Explain. 2-59a HW eTool (CPM), 2-59b HW eTool (CPM) and 2-59c HW eTool (CPM). Homework Help ✎

Use the eTool below to simplify the expressions on the Expression comparison Mat.
Click the link at right for the full version of the eTool: AC 2-69 HW eTool.

Hint:

Go through your list of legal moves and check each move made by Sylvia.

Hint:

Removing the same amount from both sides is a legal move.

Hint:

Flipping tiles from the subtraction region to the addition region and changing it from positive to negative is a legal move.

Hint:

Removing zero pairs is a legal move.

Hint:

Removing a positive tile from the (−) region and a negative tile from the (+)region is not a legal move, because they do not make a zero pair.