SOLUTION: FIND EACH PRODUCT (3Y^2 + 1) (3Y^2 - 1)

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Question 104678: FIND EACH PRODUCT
(3Y^2 + 1) (3Y^2 - 1)
Found 2 solutions by HyperBrain, Fombitz:
Answer by HyperBrain(694) About Me  (Show Source):
You can put this solution on YOUR website!
%283y%5E2+%2B+1%29%2A%283y%5E2+-+1%29

We can apply the ' difference of two squares' technique!
Thus,
%283y%5E2+%2B+1%29%2A%283y%5E2+-+1%29=%283y%5E2%29%5E2-+1%5E2
______________=9y%5E4-1

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
%283Y%5E2+%2B+1%29+%283Y%5E2+-+1%29
Use the FOIL method (First, Outer, Inner, Last)
First %28highlight%283Y%5E2%29+%2B+1%29+%28highlight%283Y%5E2%29+%2B+%28-1%29%29 : 3Y%5E2%2A3Y%5E2
Outer %28highlight%283Y%5E2%29+%2B+1%29+%283Y%5E2+%2B+highlight%28%28-+1%29%29%29 : 3Y%5E2%2A%28-1%29
Inner %283Y%5E2+%2B+highlight%281%29%29+%28highlight%283Y%5E2%29+%2B%28-1%29%29 : %281%29%2A3Y%5E2
Last %283Y%5E2+%2B+highlight%281%29%29+%283Y%5E2+%2B+highlight%28%28-1%29%29%29 1%2A%28-1%29
%283Y%5E2+%2B+1%29+%283Y%5E2+-+1%29= 3Y%5E2%2A3Y%5E2%2B3Y%5E2%2A%28-1%29%2B%281%29%2A3Y%5E2%2B1%2A%28-1%29
%283Y%5E2+%2B+1%29+%283Y%5E2+-+1%29= 9Y%5E4-cross%283Y%5E2%29%2Bcross%283Y%5E2%29-1
%283Y%5E2+%2B+1%29+%283Y%5E2+-+1%29= 9Y%5E4-1