standard_description: Solve multi-step real-life and mathematical problems posed with positive and negative rational numbers in any form (whole numbers, fractions, and decimals), using tools strategically. Apply properties of operations to calculate with numbers in any form; convert between forms as appropriate; and assess the reasonableness of answers using mental computation and estimation strategies. For example: If a woman making $25 an hour gets a 10% raise, she will make an additional 1/10 of her salary an hour, or $2.50, for a new salary of $27.50. If you want to place a towel bar 9 3/4 inches long in the center of a door that is 27 1/2 inches wide, you will need to place the bar about 9 inches from each edge; this estimate can be used as a check on the exact computation.
problem_activity: Problem 1
a.   Write two equivalent expressions to represent the total area of the rectangle shown. Justify that your two expressions are equivalent.
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b.   Expand the expression below using a rectangular array.
$${\frac{1}{3}(9x-12y-18)}$$
Problem 2
a.   What could be the missing dimensions of the rectangular array? Which set of dimensions uses the greatest common factor of the two terms?
[IMG]
b.   Factor the expression below using a rectangular array. Use the greatest common factor as the representation of the width.
$${24d-8e+6}$$
Problem 3
The table below includes expressions that are written in expanded form and in factored form. Complete the table. Use rectangular arrays as needed.
|          **           Factored Form          **          | **           Expanded Form          ** |
|----------------------------------------------------------|----------------------------------------|
|                       $$3(x-14y)$$                       |                                        |
|                                                          |               $$2x+3x$$                |
|                 $$\frac{3}{4}(8a+16b)$$                  |                                        |
|                                                          |             $$24m+8n-12p$$             |
| $$\frac{1}{2}\left(\frac{1}{3}x-8y+\frac{2}{3}z\right)$$ |                                        |
|                                                          |              $$5xy+15y$$               |
|                       $$2x(-3+y)$$                       |                                        |


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