Tìm x biết: a) x-96 = (443 – x) – 15 c) 353 – x = 46+(3x-21) e) -2.(x+6)-6.(x-10)=8 g) (-2x) . (-4x)+28= 100 Cảm ơn trước ah! ^^*

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1. Đáp án:

   a) x-96 = (443 – x) – 15

       x-96 = 443-x -15

       2x = 524

       x = 262

   c) 353 – x = 46+(3x-21)

       353-x = 46+3x-21

       4x = 353-46+21

       4x = 353

       x = 82

   e) -2.(x+6)-6.(x-10) = 8

      -2x-12-6x = 60 = 8

      -8x=-40

      x = 5

   g) (-2x) . (-4x)+28 = 100

       8x² = 72

       x²=9

       \(\left[ \begin{array}{l}x=3\\x=-3\end{array} \right.\) 

       xong

    

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2. a,$x-96=(443-x)-15$

   $⇒x-96=443-x-15$

   $⇒2x=524$

   $⇒x=262$

   c,$353-x=46+(3x-21)$

   $⇒353-x=46+3x-21$

   $⇒4x=353-46+21$

   $⇒4x=328$

   $⇒x=82$

   e,$-2.(x+6)-6.(x-10)=8$

   $⇒-2x-12-6x+60=8$

   $⇒-8x=-40$

   $⇒x=5$

   g,$(-2x).(-4x)+28=100$

   $⇒8x²=72$

   $⇒x²=9$

   ⇒\(\left[ \begin{array}{l}x=3\\x=-3\end{array} \right.\)

    

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