Evaluating Expressions for Different Values of x

5.9.1 Evaluating Expressions for Different Values of x

5.9.1 • Evaluating Expressions for Different Values of x

Warm Up

Lin and Diego are discussing two expressions: x2x2 and 2x2x.

  • Lin says, “I think the two expressions are equivalent.”
  • Diego says, “I think the two expressions are only equal for some values of xx.”
1.

Do you agree with either of them? Explain or show your reasoning.

Your answer may vary, but here is a sample:

I agree with Diego. Sample explanation: If we find the value of x2x2 and 2x2x for different values of xx, say 0, 1, 2, 3, and 4, we can see that they are not always equal. As the table shows, they are only equal sometimes, for example, when xx is 2 and 4.

xxx2x22x2x
1 1 2
2 4 4
3 9 8
4 16 16
5 25 32
10 100 1,024