Slide and Divide!!
take 2 and Slide it to 3 and multiple them
now it is z^2 - 7z +6
now salt and pepper this
-7 and 6
so it would give you numbers (-6) and (-1)
because -6 times -1 equals 6
and because -6+-1 equals -7
so then you have:
(z-6) and (z-1)
take the 2 that you slide in the earlier steps and DIVIDE it by the numbers
so now it is (z-6/2) and (z-1/2)
then its (z-3) and (2z-1)
set them both equal to zero separately
(z-3)=0 and (2z-2)=0
z=3 and z=1
then find out which one is an extrapolation