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Math Help - Adding and Subtracting Radicals

  1. #1
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    Adding and Subtracting Radicals

    How would you simplify and do these problems?

    (square root of) 2/5 + (square root of) 1/2

    8 - (square root of) 5/7

    I understand the concept... I just always get these wrong for some reason, so please be detailed so I can understand! Thanks!
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  2. #2
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    Quote Originally Posted by chandler View Post
    How would you simplify and do these problems?

    (square root of) 2/5 + (square root of) 1/2

    8 - (square root of) 5/7

    I understand the concept... I just always get these wrong for some reason, so please be detailed so I can understand! Thanks!
    Are there two separate questions there?

    Is the first one \sqrt {\dfrac{2}{5}}  + \sqrt {\dfrac{1}{2}}~?
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  3. #3
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    Yes, two seperate

    Yes, these are two different equations.

    Also... How do you make the square root symbol?
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  4. #4
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    Quote Originally Posted by chandler View Post
    How would you simplify and do these problems?

    (square root of) 2/5 + (square root of) 1/2

    8 - (square root of) 5/7

    I understand the concept... I just always get these wrong for some reason, so please be detailed so I can understand! Thanks!
    \displaystyle \sqrt{\frac{2}{5}} + \sqrt{\frac{1}{2}} = \sqrt{\frac{4}{10}} + \sqrt{\frac{5}{10}}

    \displaystyle = \frac{\sqrt{4}}{\sqrt{10}} + \frac{\sqrt{5}}{\sqrt{10}}

    \displaystyle = \frac{\sqrt{4} + \sqrt{5}}{\sqrt{10}}

    \displaystyle = \frac{2 + \sqrt{5}}{\sqrt{10}}

    \displaystyle = \frac{\sqrt{10}(2 + \sqrt{5})}{10}

    \displaystyle = \frac{2\sqrt{10} + \sqrt{50}}{10}

    \displaystyle = \frac{2\sqrt{10} + \sqrt{25}\sqrt{2}}{10}

    \displaystyle = \frac{2\sqrt{10} + 5\sqrt{2}}{10}.
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  5. #5
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    Quote Originally Posted by chandler View Post
    How do you make the square root symbol?
    [tex]\sqrt {\dfrac{2}{5}} + \sqrt {\dfrac{1}{2}}[/tex] gives \sqrt {\dfrac{2}{5}} + \sqrt {\dfrac{1}{2}}
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  6. #6
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    Thanks guys!

    One more thing...

    Please do this one too: \sqrt {\dfrac{1}{2}} + \sqrt {\dfrac{1}{2}} =
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  7. #7
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    Quote Originally Posted by chandler View Post
    One more thing...

    Please do this one too: \sqrt {\dfrac{1}{2}} + \sqrt {\dfrac{1}{2}} =
    \sqrt {\dfrac{1}{2}}={\dfrac{\sqrt2}{2}}
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