tìm số nguyên x, biết: a) |x-2|=3 b) |x+2|=3 c) |x+2|=x+2 d) |x-2|=2-x e) |x-1|=3 g) |x-12|=-1

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1. a, |x-2| = 3

   * TH1:

   x-2 = 3  (x>2)

    x = 5

   *TH2:

   x-2 = -3

   x= -1

   b) |x+2|=3

   *TH1: (x> -2)

   x+2 = 3

   x = 1

   *TH2: (x< -2)

   x+2 = -3

   x = -5

   c) |x+2|=x+2

   *TH1: (x>-2)

   x+2 = -(x+2)

   x+2 = -x-2

   2x = -4

   x = -2

   d) |x-2|=2-x

   *TH1: (x>2)

   x-2 = 2-x

   2x = 4

   x = 2

   *TH2: (x<2)

   x-2 = -(2-x)

   x-2 = -2 +x

   0x =0

   x = 0

   e) |x-1|=3

   *TH1: (x>1)

   x-1 = 3

   x = 4

   *TH2: (x<1)

   x-1 = -3

   x = -2

   g) |x-12|=-1

   *TH1: (x>12)

   x-12 = -1

   x = 11

   *TH2: (x<12)

   x-12 = 1

   x = 13

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2. |x-2|=3

   x-2=3

   x=3+2

   x=5

   b)|x+2|=3

     x+2=3

   x=3-2

   x=1

   c)|x+2|=x+2

   x+2=x+2

   d) |x-2|=2-x

        x-2=2-x

       x=0

   e) |x-1|=3

       x-1=3

       x=3+1

      x=4

   g) |x_12|=1

       x-12=1

      x=1+12

     x=13

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