1 Reply Latest reply: Mar 28, 2001 12:00 AM by TKHunny RSS

    GCF and LCM of polynomials

      how do i find the GCF and LCM of these polynomials?

      y^3-4y; y^4-8y
        • GCF and LCM of polynomials
          TKHunny Copper
          y3-4y; y4-8y

          As with every other GCF/LCM problem, your best approach MUST include a complete factorization.

          y3-4y = y�(y2-4) = y�(y+2)�(y-2)

          y4-8y = y�(y3-8) = y�(y-2)�(y2+2y+4)

          The LCM Zone

          The LCM is the collection of factors that JUST contains each factor of each element. No need to count a factor from one element if it is already included in a previous element.

          Just copy the first one:


          Then add whatever it does not have, that the other does.

          yskip this one�(y-2)skip this one�(y2+2y+4)use this one


          Gives the LCM

          The GCF Zone

          GCF is the collection of factors that are common to all elements.


          Both have a 'y'
          Both have a 'y-2'

          That's it.

          y�(y-2) is the GCF