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(x + 4)(5x + 3) Multiply, showing your work using the Area model.

a) 5x^2 + 17x + 12
b) 5x^2 + 15x + 12
c) 5x^2 + 23x + 12
d) 5x^2 + 13x + 12

1 Answer

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Final answer:

By using the Area model to multiply the expressions (x + 4) and (5x + 3), and adding the results from the four areas, we get the polynomial 5x^2 + 23x + 12, which is option c).

Step-by-step explanation:

To multiply the expressions (x + 4) and (5x + 3) using the Area model, we set up a rectangle divided into four smaller rectangles. Each side of the larger rectangle is divided into two parts: one for each term of the respective binomial.

In the top row, one smaller rectangle will represent the area (x * 5x) and another, the area (x * 3). In the bottom row, the corresponding smaller rectangles represent the areas (4 * 5x) and (4 * 3).

Multiplying the terms in each of the smaller rectangles, we get:

  • x * 5x = 5x2
  • x * 3 = 3x
  • 4 * 5x = 20x
  • 4 * 3 = 12

Adding these areas together (or adding the like terms), we get 5x2 + 3x + 20x + 12, which simplifies to 5x2 + 23x + 12.

Therefore, the answer to the multiplication of (x + 4)(5x + 3) using the Area model is 5x2 + 23x + 12, which corresponds to option c).

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