Use a geometric model to factor [tex]2x^2 - x - 1[/tex] by following these steps:

Step 1: Model the polynomial by placing tiles in the Product section.
- [tex]+x^2[/tex]
- [tex]-x[/tex]
- [tex]-1[/tex]



Answer :

To factor the quadratic polynomial [tex]\(2x^2 - x - 1\)[/tex] using a geometric model, we will follow a series of steps. Here's the detailed, step-by-step solution:

### Step 1: Initial Placement of Tiles

1. Model the polynomial by placing tiles in the Product section.
- We start by representing each term of the given polynomial [tex]\(2x^2 - x - 1\)[/tex] with tiles:

- [tex]\(2x^2\)[/tex]: Place two [tex]\(x^2\)[/tex] tiles in the Product section.
- [tex]\(-x\)[/tex]: Place one [tex]\(-x\)[/tex] tile, splitting it into two pieces of [tex]\(-\frac{x}{2}\)[/tex] each to facilitate arrangement later.
- [tex]\(-1\)[/tex]: Place one [tex]\(-1\)[/tex] tile in the Product section.

### Step 2: Arrange the Tiles to Form a Rectangle

2. Arrange the tiles in such a way that they form a rectangle.
- Combine and adjust the tiles to form a rectangle. This process helps in visualizing the factors of the polynomial.

Let’s map the pieces to form the rectangle:

- Arrange the two [tex]\(x^2\)[/tex] tiles side by side.
- Place the [tex]\(-\frac{x}{2}\)[/tex] tiles such that they share sides with the [tex]\(x^2\)[/tex] tiles.
- Finally, place the [tex]\(-1\)[/tex] tile to complete the rectangle.

### Step 3: Identify the Dimensions of the Rectangle

3. Identify the dimensions (factors of the polynomial) from the arrangement:

- Check the dimensions by examining the way the tiles are arranged.
- One dimension can be identified by combining the length of one [tex]\(x^2\)[/tex] tile and one dimension of the [tex]\(-\frac{x}{2}\)[/tex] pieces.
- The remaining dimension can be found by the other sides of the arranged tiles that fit together to form the rectangle.

### Step 4: Write the Polynomial in Factored Form

4. Convert the dimensions identified in Step 3 into algebraic expressions to write the polynomial in factored form:

- From the arrangement, we have identified two dimensions as:
- [tex]\((x - 1)\)[/tex]
- [tex]\((2x + 1)\)[/tex]

Thus, the quadratic polynomial factors into:

[tex]\[ (x - 1)(2x + 1) \][/tex]

### Conclusion

Therefore, the polynomial [tex]\(2x^2 - x - 1\)[/tex] factors into:

[tex]\[ (x - 1)(2x + 1) \][/tex]

This is the factored form of the quadratic polynomial.