Question

Tìm x\(\in\) Z biết :

1) x - 2 = -6

2) -5x - (-3) = 13

3) 15 - (x -7) = - 21 

4) 3x + 17 = 2

 

Answer 1

1) x-2=-6

       x=-6+2=-4

2)-5x-(-3)=13

        -5x =13+(-3)=10

          x=10:(-5)=-2

3) 15-(x-7)=-21

         x-7=15-(-21)=36

           x=7+36=43

4) 3x+17=2

           3x=2-17=-15

           x=-15:3=-5

Answer 2

1) x-2 = 6

<=> x = 6+2 =8

2) -5x-(-3)=13

<=> -5x+3 =13

<=> -5x=13-3=10

<=> x = 10:(-5)

<=> x=-2

3) 15-(x-7)=-21

<=> x-7 = 15 -(-21) =36

<=> x = 36 +7 = 43

4) 3x+17 = 2

<=> 3x = 2-17 =-15

<=> x=-15 :3 = -5

Answer 3

1) x-2=-6

    x   =-6+2

    x   =-4

2) -5x-(-3)=13

     -5x     =13+(-3)

      -5x    =10

       x      =10:(-5)

       x      =-2

3) 15-(x-7)=-31

     x-7      =15-(-31)

     x-7      =46

     x          =46+7

      x         =53

4) 3x+17=2

    3x      =2-17

     3x     =-15

      x      =-15:3

      x       =-5

Answer 4

1) x=-4

2) x=-2

3) x=29

4)  x=-5

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Answer 5

1) x - 2 = - 6

=> x = - 6 + 2

=> x = - 4 (tm)

2) - 5x - (- 3) = 13

=> - 5x + 3 = 13

=> - 5x = 10

=> x = - 2 (tm)

3) 15 -(x - 7) = -21

=> -(x - 7) = 36

=> -x + 7 = 36

=> - x = 29

=> x = -29(tm)

4) 3x + 17 = 2

=> 3x = - 15

=> xx = - 5 (tm)

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Answer 6

1) x-2=-6 =>x=-4

2)-5x-(-3)=13 

   -5x+3=13

   -5x=10

   x=-2

3)15-(x-7)=-21

       x-7=36

       x=43

4)3x+17=2

   3x=-15

Answer 7

1)x-2=-6

=> x=-6+2

=>x=-4

2)-5x-(-3)=13

=>-5x+3=13

=>-5x=13-3

=>5x=10

=>x=10/5

=>x=2

3)15-(x-7)=-21

=>15-x+7=-21

=>15-x=-21-7

=>15-x=-28

=>-x=-28-15

=>-x=-43

=>x=43

4)3x+17=2

=>3x=2-17

=>3x=-15

=>x=-15/3

=>x=-5