To evaluate which models represent algebraic expressions equivalent to the original model, let's analyze the components of the first model you described:
- 3 rectangles labeled x
- 2 rectangles labeled -x
- 5 squares labeled 1
- 2 squares labeled -1
Now, let's translate these into an algebraic expression:
-
The total contribution from the rectangles:
- \(3x\) for the \(3\) rectangles labeled \(x\)
- \(2(-x)\) or \(-2x\) for the \(2\) rectangles labeled \(-x\)
Combining these gives: \[ 3x - 2x = x \]
-
The total contribution from the squares:
- \(5(1)\) or \(5\) for the \(5\) squares labeled \(1\)
- \(2(-1)\) or \(-2\) for the \(2\) squares labeled \(-1\)
Combining these gives: \[ 5 - 2 = 3 \]
Thus, the overall expression represented by the model is: \[ x + 3 \]
Now we need to find equivalent expressions among the provided options:
-
Option: \(2 rectangles, each labeled x, 2 rectangles, each labeled -x, 2 squares, each labeled 1, and 2 squares, each labeled -1\)
- This translates to:
- \(2x - 2x + 2 - 2 = 0\)
- Not equivalent to \(x + 3\).
- This translates to:
-
Option: \(2 rectangles, each labeled x, 1 rectangle labeled -x, 4 squares, each labeled 1, and 1 square labeled -1\)
- This translates to:
- \(2x - x + 4 - 1 = x + 3\)
- This is equivalent to \(x + 3\).
- This translates to:
-
Option: \(3 rectangles, each labeled x, 1 rectangle labeled -x, 5 squares, each labeled 1, and 1 square labeled -1\)
- This translates to:
- \(3x - x + 5 - 1 = 2x + 4\)
- Not equivalent to \(x + 3\).
- This translates to:
-
Option: \(1 rectangle labeled x and 1 square labeled 1\)
- This translates to:
- \(x + 1\)
- Not equivalent to \(x + 3\).
- This translates to:
-
Option: \(1 rectangle labeled x and 3 squares, each labeled 1\)
- This translates to:
- \(x + 3\)
- This is also equivalent to \(x + 3\).
- This translates to:
Thus, the two correct answers are:
- Option 2: \(2 rectangles, each labeled x, 1 rectangle labeled -x, 4 squares, each labeled 1, and 1 square labeled -1\)
- Option 5: \(1 rectangle labeled x and 3 squares, each labeled 1\)