Use algebra tiles to find the product of (x−5)^2

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1 answer

To find the product of \((x - 5)^2\) using algebra tiles, we can interpret the expression as \((x - 5)(x - 5)\). We'll use the following steps to visualize it:

  1. Understanding the expression: The expression \((x - 5)\) represents a binomial, meaning it consists of two parts: \(x\) and \(-5\).

  2. Setting up the algebra tiles:

    • Consider \(x\) as a large tile representing \(x\).
    • The \(-5\) can be represented as five smaller tiles, each representing \(-1\).
  3. Arrange the tiles:

    • On a rectangular grid, arrange two \(x\) tiles horizontally on the top row.
    • Below the \(x\) tiles, place two groups of \(-5\) tiles extending out from each \(x\) tile.
  4. Finding the area: The area of the arrangement represents the product \((x - 5)(x - 5)\).

    • First, multiply the \(x\) terms:
      • \(x \cdot x = x^2\)
    • Next, calculate the interaction:
      • \(x \cdot -5\) gives \(-5x\)
      • The second \(x \cdot -5\) gives another \(-5x\)
    • Finally, the product of the \(-5\) tiles:
      • \(-5 \cdot -5 = 25\)
  5. Combine the results:

    • From the above, you get:
      • \(x^2\) from the \(x \cdot x\)
      • \(-5x - 5x = -10x\) from the two interactions
      • And finally, \(+25\) from the \(-5 \cdot -5\)

Putting it all together, you get the expression:

\[ (x - 5)^2 = x^2 - 10x + 25 \]

Thus, the product of \((x - 5)^2\) is:

\[ x^2 - 10x + 25 \]