Averi was trying to factor


. She found that the greatest common factor of these terms was

and made an area model:
An area model for a rectangle with a height of four and an unknown width. The rectangle is broken into three rectangles to isolate each term in the width. The first rectangle has a height of four and an area of four x squared. The second rectangle has a height of four and an area of twenty x. The third rectangle has a height of four and an area of negative sixteen.





What is the width of Averi's area model?

1 answer

To find the width of Averi's area model, we start with the individual areas of the rectangles that represent the terms in the polynomial. We know that the height of the rectangles is 4, and we want to determine the width of the entire rectangle.

Averi's area model shows three rectangles with given areas:

  1. The first rectangle has an area of \(4x^2\).
  2. The second rectangle has an area of \(20x\).
  3. The third rectangle has an area of \(-16\).

Since the area of each rectangle is given by the formula:

\[ \text{Area} = \text{Height} \times \text{Width} \]

we can set up equations to find the widths of each rectangle.

Finding Individual Widths:

  1. For the first rectangle: \[ 4 \times \text{Width}_1 = 4x^2 \implies \text{Width}_1 = \frac{4x^2}{4} = x^2 \]

  2. For the second rectangle: \[ 4 \times \text{Width}_2 = 20x \implies \text{Width}_2 = \frac{20x}{4} = 5x \]

  3. For the third rectangle: \[ 4 \times \text{Width}_3 = -16 \implies \text{Width}_3 = \frac{-16}{4} = -4 \]

Combining the Widths:

The total width of the area model is the sum of the widths of the individual rectangles: \[ \text{Total Width} = \text{Width}_1 + \text{Width}_2 + \text{Width}_3 \] Substituting in the width values: \[ \text{Total Width} = x^2 + 5x - 4 \]

Thus, the width of Averi's area model is: \[ \boxed{x^2 + 5x - 4} \]