a)|x+1/2| – 4/5 = 0 b) |x-1,2|.5 = 0 c) |1/2 – x|-1/2 =0 d) |3 – x| . 7 = 0

0 bình luận về “a)|x+1/2| – 4/5 = 0 b) |x-1,2|.5 = 0 c) |1/2 – x|-1/2 =0 d) |3 – x| . 7 = 0”

1. `a)`

   `|x+1/2| – 4/5 = 0`

   ` | x + 1/2 |  – 4/5 = 0`

   `| x + 1/2| = 0 + 4/5`

   `| x  + 1/2|  = 4/5`

   \(\left[ \begin{array}{l}x+\frac{1}{2} = \frac{4}{5} \\x+\frac{1}{2} = \frac{-4}{5}\end{array} \right.\)

   \(\left[ \begin{array}{l}x=3\\x=\frac{-13}{14}\end{array} \right.\)

   `b)`

   `|x-1,2|.5 = 0`

   `x- 1,2 . 5 = 0`

   `x=  0: 5  +1,2`

   `x = 1,2`

   `c)`

   `|1/2 – x|-1/2 =0`

   `|x – 1/2| = 1/2 – 0`

   `|x – 1/2 | = 1/2`

   \(\left[ \begin{array}{l}x -\frac{1}{2 } =\frac{1}{2}\\x -\frac{1}{2 } =\frac{-1}{2}\end{array} \right.\)

   \(\left[ \begin{array}{l}x=1\\x=0\end{array} \right.\)

   `d)`

   `|3 – x| . 7 = 0`

   `|3 -x| = 0 :7`

   `|3 – x| = 0`

   `3 – x =0`

   `x = 3 -0`

   `x = 3`

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2. |x+1/2|-4/5=0

   |x+1/2|        =0+4/5

   |x+1/2|        =4/5

   x+1/2=4/5 hoặc             x+1/2=-4/5

   x         =4/5-1/2                     x =(-4/5)-1/2

   x         =8/10-5/10                x  =-8/10-5/10

   x         =3/10                         x  =-13/10

   b)|x-1,2|.5=0

       |x-1,2|   =0:5

        |x-1,2|   =0

        x-1,2=0 

         x     =0+1,2

         x    1,2

   c)|1/2-x|-1/2=0

      |1/2-x|        =0+1/2

      |1/2-x|        =1/2

      1/2-x           =1/2 hoặc 1/2-x=–1/2

             x            =1/2-1/2         x=1/2–1/2

             x            = 0                   x=1 

   d)|3-x|.7=0

       |3-x|   =0:7

       |3-x|    =0

       3-x=0 

       x    =3-0

       x=3      

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