Question

Tìm x :

x - ( 17 - x ) = x + 3

- ( x + 12 ) + 35 = - 47

15 - ( x + 32 ) = - 11

Answer 1

x - ( 17 - x ) = x + 3

<=> 2x - 17  = x + 3 

<=> x = 20

Vậy x = 20

- ( x + 12 ) + 35 = - 47

<=> - x - 12 = - 47 -35

<=> x = 47 + 35 - 12

<=> x = 60

Vậy x = 60

15 - ( x + 32 ) = - 11

<=> 15 - x - 32 = - 11

<=> - x - 17 = - 11

<=> - x = - 11 + 17 = 6

<=> x = - 6

Vậy x = - 6

K chắc lắm

Answer 2

a)\(x-\left(17-x\right)=x+3\)

\(\Leftrightarrow x-17+x=x+3\)

\(\Leftrightarrow x+x-x=17+3\)

\(\Leftrightarrow x=20\)

b)\(-\left(x+12\right)+35=-47\)

\(\Leftrightarrow-x-12+35=-47\)

\(\Leftrightarrow-x=-47+12-35\)

\(\Leftrightarrow-x=-70\)

\(\Leftrightarrow x=70\)

c)\(15-\left(x+32\right)=-11\)

\(\Leftrightarrow15-x-32=-11\)

\(\Leftrightarrow-x=-11-15+32\)

\(\Leftrightarrow-x=6\)

\(\Leftrightarrow x=-6\)

Answer 3

x - ( 17 - x ) = x + 3

   x - 17 + x = x + 3

   x + x - x   = 3 + 17

              x   = 20

Vậy x = 20

- ( x + 12 ) + 35 = - 47

     - x - 12 + 35 = - 47

                    - x = - 47 + 12 - 35

                    - x = - 70

                      x = 70

Vậy x = 70

15 - ( x + 32 ) = - 11

         x + 32   = 15 - ( - 11 )

         x + 32   = 26

                x    = 26 - 32

                x    = - 6

Vậy x = - 6