a) ( a – 2009 ) ² + ( b + 2010 ) ² = 0 b) | a – 2010 | = 2009

a) ( a – 2009 ) ² + ( b + 2010 ) ² = 0
b) | a – 2010 | = 2009

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  1. a) $(a-2009)^2≥0$

        $(b+2010)^2≥0$

    mà $(a-2009)^2+(b+2010)^2=0$

    \(⇒\left[ \begin{array}{l}(a-2009)^2=0\\(b+2010)^2=0\end{array} \right.\)

    \(⇒\left[ \begin{array}{l}a-2009=0\\b+2010=0\end{array} \right.\)

    \(⇒\left[ \begin{array}{l}a=2009\\b=-2010\end{array} \right.\)

    Vậy $(a,b)=(2009,-2010)$

    b) $|a-2010|=2009$

    \(⇒\left[ \begin{array}{l}a-2010=2009\\a-2010=-2009\end{array} \right.\)

    \(⇒\left[ \begin{array}{l}a=4019\\a=1\end{array} \right.\)

    Vậy $a=(4019,1)$

     

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  2. $a$) $(a-2009)^2 + (b+2010)^2 = 0$

    Vì : $(a-2009)^2;(b+2010)^2 ≥ 0 ∀ a;b$

    $⇒ a-2009=b+2010=0$

    $⇒ a = 2009;b=-2010$

      Vậy `(a;b);(2009;-2010)`

    $b$) `|a – 2010| = 2009`

    `⇔` \(\left[ \begin{array}{l}a=4019\\a=1\end{array} \right.\) 

      Vậy $a$ $∈$ `{4019;1}`

     

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