### Home > CC2 > Chapter 6 > Lesson 6.1.1 > Problem 6-6

6-6.

Write the expression shown on each of the Expression Mats below. Then simplify them by making zeros and combining like terms.

Notice that a grey tile and a white tile of the same value cancel each other out and make a zero.

**Circle around the positive x and the negative x tiles, with the tiles crossed out, labeled 0. A second circle around the positive unit and the negative unit tiles, with the tiles crossed out, labeled 0.**Now write an expression for the values that remain.

**A circle is added around the remaining 2 unit tiles.**

See part (a).

Use the eTool below to solve part (a).

Click the link at right for the full version of the eTool: *6-6 HW eTool* (CPM)