Question

Tìm x thuộc Z,biết

a,5x+8=2x-7                             b,3.(x+2)=2.(x-1)

Làm giúp mk bài này nha!Cảm ơn mn nhìu nha:3

Answer 1

a,5x+8=2x-7                         

5x+8-2x+7=0

<=>3x+15=0

<=>3x=-15

<=>x=-5

Vậy x=-5

   b,3.(x+2)=2.(x-1)

<=>3x+6=2x-1

<=>3x+6-2x+1=0

<=>x+7=0

<=>x=-7

Vậy x=-7

Answer 2

a,5x+8=2x-7

   5x - 2x = -7 - 8

    3x        = -15

      x        = (-15) : 3

      x        = -5

Vậy x = -5

 b,3.(x+2)=2.(x-1)

    3x + 6 = 2x - 2

    3x - 2x= -2 - 6

       x     = -8

Vậy x = -8

# HOK TỐT #

Answer 3

\(a,5x+8=2x-7\)

<=>\(5x-2x=\left(-7\right)-8\)

<=>\(3x=-15\)

<=>\(x=-5\)

\(b,3\left(x+2\right)=2\left(x-1\right)\)

<=>\(3x+6=2x-2\)

<=>\(3x-2x=\left(-2\right)-6\)

<=>\(x=-8\)

Answer 4

\(a,5x+8=2x-7\)

\(5x-2x=-7-8\)

\(3x=-15\Leftrightarrow x=-5\)

\(b,3\left(x+2\right)=2\left(x-1\right)\)

\(3x+6=2x-2\)

\(3x-2x=-2-6\)

\(x=-8\)

Answer 5

a,5x+8=2x-7                       

   5x-2x=-7-8

   3x=-15

     x=-15:3

     x=-5

Vậy x=-5     

b,3.(x+2)=2.(x-1)

   3x+6=2x-2

   3x-2x=-2-6

          x=-8

Vậy x=-8