31 - #2

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31 - #2

by magical cook » Sun Aug 19, 2007 8:59 pm
Hi,

The answer to this question is A but I just wonder what if the equation is (2^12+2^6)/(2^6-2^3) or (2^12-2^6)/(2^6+2^3)? (+ and - is mixed case..)

Can anyone help me understand?

Thanks!
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Re: 31 - #2

by gabriel » Sun Aug 19, 2007 11:46 pm
magical cook wrote:Hi,

The answer to this question is A but I just wonder what if the equation is (2^12+2^6)/(2^6-2^3) or (2^12-2^6)/(2^6+2^3)? (+ and - is mixed case..)

Can anyone help me understand?

Thanks!
we know that (a^2-b^2)= (a-b)(a+b) .. similarly (2^12-2^6)=(2^6-2^3)(2^6+2^3) ...

..So when u divide the expression (2^12-2^6) by (2^6-2^3) the answer is (2^6+2^3) ..

.. and if we divide the expression (2^12-2^6) by (2^6+2^3) .. the answer will be (2^6-2^3)

.. now, it wont be as easy with (2^12+2^6) bcoz this expression doesnt have a set formula that will help us get the answer directly ... but it still can be solved using a combination of formulas and long division method ...

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by devesh » Mon Aug 20, 2007 12:49 am
The answer to this question is A but I just wonder what if the equation is (2^12+2^6)/(2^6-2^3) or (2^12-2^6)/(2^6+2^3)? (+ and - is mixed case..)

(2^12-2^6)/(2^6+2^3)? is no issue use (a+b)(a-b)

(2^12+2^6)/(2^6-2^3) can be simplified only by removing 2's

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by magical cook » Wed Aug 22, 2007 11:33 am
Got it - thanks both for explanation :)