2x - 15 = -11 - ( -16 )

2x - 15 = -11 + 16 

2x - 15 = 5

2x         = 5 + 15 

2x         = 20

   x        = 20 : 1 

   x        = 10 

Vậy x = 10

7 - 2x = -37 - ( -26 )

7 - 2x = -37 + 26

7 - 2x = -11

      2x = 7 - ( - 11 )

      2x = 7+ 11

      2x = 18

        x = 18 : 2 

        x = 9

Vậy x = 9 

| x + 7 | = 9 

TH1 :

x + 7 = 9

=> x  = 9 - 7 

=> x  = 2    

TH2 :

x - 7 = -9

=> x  = -9 - 7

=> x  = - 9 + ( -7 )

=> x   = -16 

Vậy x = 2 và x = -16

Câu cuối bn tự làm nha! ^-^

2x-15=-11-(-16)

2x-15= -11+16

2x-15=5

2x=5+15

2x=20

x=20:2

x=10

\(2x-15=-11-\left(-16\right)\)

\(\Leftrightarrow2x-15=5\)

\(\Leftrightarrow2x=5+15\)

\(\Leftrightarrow2x=20\)

\(\Leftrightarrow x=20\div2\)

\(\Leftrightarrow x=10\)

\(-7-2x=-37-\left(-26\right)\)

\(\Leftrightarrow-7-2x=-11\)

\(\Leftrightarrow2x=-7+11\)

\(\Leftrightarrow2x=4\)

\(\Leftrightarrow x=\frac{4}{2}\)

\(\Leftrightarrow x=2\)

a) x - 12 - 2x - 32 = -11

-x - 44 = -11

-x  = 33

x = -33 

a/ (x-12)-(2x+31)=-6-5

    x-12-2x-31=-11

    -x=(-11)+43

-x=32

=> x=-32

a/ (x-12)-(2x+31)=-6-5

    x-12-2x-31=-11

    -x=(-11)+43

-x=32

=> x=-32

7+2x=-37-(-26)-x

7+2x=-11-x

7+2x+x=-11

7+3x=-11

3x=-11-7

3x=-18 

x=-18:3

x=-6

a) 0,4:x=x:0,9

0,4.0,9=x²

0,36 =x²

\(\sqrt{0,36}\)=x

0,6 =x

a) 0,4 : x = x : 0,9 x^2=0,9 . 0,4 x^2=(0,6)^2 =>x=+_6

\(7+2x=-37-\left(-26\right)-x\)

\(7+2x=-11-x\)

 \(2x+x=-11-7\)

         \(3x=-18\)

           \(x=\left(-18\right):3\)

           \(x=-6\)

Vậy \(x=-6\)

7+2x=-37-(-26)-x

7+2x=-11-x

7+2x+x=-11

7+3x=-11

3x=-11-7

3x=-18

x=-18:3

x=-6

-7-2x = 37-(-26)

Suy ra -7-2x=11

Suy ra -2x=11-7

Suy ra -2x=4

Suy ra 2x= -4

Suy ra x = -4 :2 =-2

2: x=3

3: x=18

1) \(x=51\)

2) \(x=3\)

3) \(x=18\)

4) \(x=2\)

5) \(x=7\)