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Show that the following expressions are not equivalent using TWO different methods: (x + 3)^2 and x^2 + 9.

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Final answer:

By expanding the binomial (x + 3)^2, we found it equals x^2 + 6x + 9, which has an additional term 6x not found in x^2 + 9. Additionally, evaluating both expressions with x = 1 yields different results, confirming they are not equivalent.

Step-by-step explanation:

We will show that the expressions (x + 3)^2 and x^2 + 9 are not equivalent using two different methods.

Method 1: Expand the Binomial

First, we will expand the binomial:

(x + 3)^2 = x^2 + 2(3)x + 3^2 = x^2 + 6x + 9

Comparing this with x^2 + 9, we can see there is an extra term, 6x, which is not present in x^2 + 9. Hence, the two expressions are not equivalent.

Method 2: Evaluate with a Specific Value

Next, let's evaluate both expressions using a specific value for x. Let x = 1:

  • (1 + 3)^2 = (4)^2 = 16
  • 1^2 + 9 = 1 + 9 = 10

The results are different, so the expressions are not equivalent. This demonstrates that regardless of the value chosen for x, the two expressions will yield different results unless by coincidence.

User Ray Fitzgerald
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