Simplify this

6x-3y-z+2x+3y-7z

8x - 8z.

Step-by-step explanation:

Let's first rearrange 6x-3y-z+2x+3y-7z where all the x's are together, all y's together, and all z's are together:

6x + 2x + 3y - 3y - z - 7z.

First we combine like terms.

6x + 2x ⇒ 8x

3y - 3y ⇒ 0

z - 7z ⇒ - 8z.

Since the y's result in 0, we do not include them.

Therefore, our answer is 8x - 8z.