Gee whiz. That's visually a bit daunting, but we are doing the exact same thing; we need to take it piece by piece. The number part will be the largest constant that divides 6, 9, and 15, which is 3. The variable *x* occurs once in the first term, twice in the second, and not at all in the third, and we don't get to use any copies of *x*. The variable *y* occurs three times in the first term, three times in the second term, and twice in the third term, and we get two copies of *y*. The variable *z* does not occur in the first two terms, and we don't get any copies of *z*. We can conclude that the greatest common factor for this expression is 3*y*^{2}. It is a shame, really...*z* hardly ever gets any time in the spotlight, and here he is getting dissed again. Chin up, *z*. Your time will come. | |