Question

[๖ۣۜкαŋşʉкε♡]

Bài 48: Tìm số nguyên x, biết:

a) | x + 2| = 0                                                                 b) | x - 5| = |-7|

c) | x - 3 | = 7 - ( -2)                                                        d) ( 7 - x) - ( 25 + 7 ) = - 25

e) | x - 3| = |5| + | -7|                                                       g) 4 - ( 7 - x) = x - ( 13 -4) : 

Answer 1

[Hoàng hôn ( Cool Team )]

a) | x + 2| = 0        

=>x+2=0

        x=0-2

        x=-2

Vậy x=-2

b) | x - 5| = |-7|

    |x-5|=7

\(\Rightarrow\orbr{\begin{cases}x-5=7\\x-5=-7\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=7+5=12\\x=-12+5=-7\end{cases}}\)

Vậy..............................................

c) | x - 3 | = 7 - ( -2)                         

    | x-3|=9

* x-3=9             *x-3=-9

      x=9+3              x=-9+3

      x=12                x=-6

Vậy........................................                

d) ( 7 - x) - ( 25 + 7 ) = - 25

    (7-x)-32=-25

     7-x=-25+32

     7-x=7

        x=7-7

        x=0

Vậy x=0

e) | x - 3| = |5| + | -7|

     |x-3|=12

* x-3=12                  * x-3=-12

      x=12+3                    x=-12+3

      x= 15                        x=-9

Vậy...............................................                               

g) 4 - ( 7 - x) = x - ( 13 -4) 

    4-7-x=x-9

    3-x=x-9

    3+9=x+x

     12=2x

       x=12:2

       x=6

Vậy x=6

Answer 2

[๖²⁴ʱんuﾘ ｲú❄✎﹏]

\(a,|x+2|=0\Leftrightarrow x+2=0\Leftrightarrow x=-2\)

\(b,|x-5|=|-7|\)

\(\Leftrightarrow|x-5|=7\Leftrightarrow\orbr{\begin{cases}x-5=7\\x-5=-7\end{cases}\Rightarrow\orbr{\begin{cases}x=12\\x=-2\end{cases}}}\)

\(c,|x-3|=7-\left(-2\right)\)

\(|x-3|=9\Leftrightarrow\orbr{\begin{cases}x-3=9\\x-3=-9\end{cases}\Leftrightarrow\orbr{\begin{cases}x=12\\x=-6\end{cases}}}\)

\(d,\left(7-x\right)-\left(25+7\right)=-25\)

\(\left(7-x\right)-32=-25\)

\(7-x=7\Leftrightarrow x=0\)

\(e,|x-3|=|5|+|-7|\)

\(|x-3|=12\Leftrightarrow\orbr{\begin{cases}x-3=12\\x-3=-12\end{cases}\Leftrightarrow\orbr{\begin{cases}x=15\\x=-9\end{cases}}}\)

\(g,4-\left(7-x\right)=x-\left(13-4\right)\)

\(4-7+x=x-13+4\)

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

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

\(-2x=-14\)ko chắc chỗ này vì -x-x=-2x nha bn 

\(x=7\)