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Number properties

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Source: — Problem Solving |

by [email protected] » Sun Sep 20, 2015 7:26 pm
Hi sud21,

These types of questions are essentially about 're-organizing' the information (in this case, by factoring and using exponent rules).

We start with

5^8 + 10^6 - 50^3

We can leave the first term 'as is' and re-write the second and third 'terms'...

5^8 + (2^6)(5^6) - (2^3)(5^3)(5^3) =

5^8 + (2^6)(5^6) - (2^3)(5^6)

Next, we can factor 5^6 out of each term....

(5^6)[5^2 + 2^6 - 2^3]

Since the terms in the bracket are relatively small, we can calculate and simplify...

(5^6)[25 + 64 - 8]

(5^6)[81]

The 81 can be rewritten....

(5^6)[3^4]

Thus, the smallest prime factor is 3...

Final Answer: B

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Rich
Contact Rich at [email protected]
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by Matt@VeritasPrep » Thu Sep 24, 2015 10:40 am
5� + 10� - 50³ =

5� * (5² + 2� - 2³) =

5� * (25 + 64 - 8) =

5� * 81 =

5� * 3�
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