# G.5.6.2 Perfectly Square

- Author:
- Katie Akesson

- Topic:
- Square

Apply the distributive property to each expression. a. (x - 7)(x - 7) b. (x + 4)² c. (x - 10)² d. (x + 1)²

Look at your results from above. Each of these expressions is called a *perfect square trinomial*. Why?

Which of these expressions are perfect square trinomials? If you get stuck, look for patterns in your earlier work. a. x² - 6x + 9 b. x² + 10x + 20 c. x² + 18x + 81 d. x² - 2x +1 e. x² + 4x + 16

Explain to a student who was absent how to find which trinomials are perfect squares, and strategies for rewriting those expressions as perfect squares.

Rewrite the perfect square trinomials you identified as squared binomials.

Imagine you were looking at the work of a peer who incorrectly rewrote x² - 8x + 16 as (x - 8)². How could this student check their work? What should the correct answer be?