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Thread: Subtracting Mixed Numbers

  1. #1
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    Subtracting Mixed Numbers

    Does anybody know how to do this without using square roots? I am terrible at square roots and they confuse me but anyway I've see to solve it involves square roots.
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  2. #2
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    Re: Subtracting Mixed Numbers

    $2^{5/2} - 2^{3/2}= 2(2^{3/2})-2^{3/2} = (2-1)2^{3/2} = 2^{3/2}$
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  3. #3
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    Re: Subtracting Mixed Numbers

    Quote Originally Posted by whytbh View Post
    Does anybody know how to do this without using square roots? I am terrible at square roots and they confuse me but anyway I've see to solve it involves square roots.
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    $\Large{2^{\frac{5}{2}}-2^{\frac{3}{2}}}=2^{\frac{3}{2}}\left(2^{\frac{2}{ 2}}-1\right)=?$
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  4. #4
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    Re: Subtracting Mixed Numbers

    The simplest way to do this is the use the "laws of exponents"- in particular the fact that x^{ab}= (x^a)^b. Here, you have 2^{5/2)= 2^{5(1/2)}= (2^{1/2})^5 and 2^{3/2}= 2^{3(1/2)}= (2^{1/2}^3. We can write the expression as (2^{1/2})^5- (2^{1/2})^3 and factor out (2^{1/2})^3 ( 2^{5/2}= 2^{3/2+ 2/2}= 2^{1+ 3/2}.)

    2^{5/2}- 2^{3/2}= (2^{3/2})(2- 1)= 2^{3/2}.
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