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Re: (999999)^2 - 1^2= [#permalink]
999999^2 - 1^2 = (999999 + 1)(999999 - 1 ) , right ??
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Re: (999999)^2 - 1^2= [#permalink]
yes... in fact:
10^6*(10^6-2)=10^6*999,998=(999999 + 1)(999999 - 1 )
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Re: (999999)^2 - 1^2= [#permalink]
VERY NICE!!!

Let's also remember that trick if it were to be 999999^2 -1.

Even if the question is not written as 1^2, we can re-write the question to nail this one!!!
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Re: (999999)^2 - 1^2= [#permalink]
(999999)^2 can be calculated easily by doing it in a straightforward way

9*9 = 81
99*99 = 9801
999*999 = 998001
hence
999999*999999 = 999998000001 :-D
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Re: (999999)^2 - 1^2= [#permalink]
bono wrote:
(999999)^2 can be calculated easily by doing it in a straightforward way

9*9 = 81
99*99 = 9801
999*999 = 998001
hence
999999*999999 = 999998000001 :-D



good.....but the answer choices do not require u to solve it this way.See my comments above.

The way javropu solved it is the right way.......



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