magellan333 wrote:The instructions were to find the LCD of the three. I factored as follows:

X-7 = x-7

3x-21 = 3(x-7)

6x=6x

Therefore my answer was x-7, 3 and 6x.

Okay. Now, after you've read the lesson in the link and factored the 6 in the 6x, what are you getting?