2004 NO.38
Find the LCM of (2-b) (4-b^2) (8-b^3).
There must be at least one that can factorized into another form. In this question we consider the middle one first.
(4-b^2)=(2^2-b^2) =(2+b)(2-b)
then the third one
(8-b^3) =(2^3-b^3) =(2-b)(2^2+2xb+b^2)
...
You can then work out the answer.
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