b) 25 -2x =27

2x =27-25

2x= 2

x= 2:2

x=1

Vậy...

Câu 1 thiếu đề r bn

b,  25 - 2x = 27

   =) 2x = 25 - 27 = -2

  =) x = -2 : 2 = -1

c) 29 -x = -30 

x= 29 -( -30)

x= 59

Vậy....

1,7-(18+x)=-15

<=>18+x=7+15

<=>18+x=22

<=>x=4

2,(x-17)-(-3)=0

<=>x-17+3=0

<=>x-17=-3

,<=>x=14

<=>

1, 

7 - ( 18 + x ) = - 15 

18 + x = 7 + 15 

18 + x = 22

x = 22 - 18 

x = 4 

2,

( x - 17 ) - ( - 3 ) = 0 

( x - 17 ) + 3 = 0 

x - 17 = - 3 

x = -3 + 17 

x = 14 

3, -18 - ( x - 6 ) = 0 

-18 = x- 6 

x = - 18 + 6 

x = - 12 

4,   29 - ( 10 + 29 ) = x - ( 27 - 9 )

-10 = x - 18 

x = - 10 + 18 

x = 8

a) -84 - (-18 - 6) = x + (-20)

      -84 + 18 + 6 = x - 20

    -84 + 18 + 6 + 20 = x

                         => x = -40

\(-84-\left(-18-6\right)=x+\left(-20\right)\)

\(\Leftrightarrow x=\left(-20\right)+84+\left(-18-6\right)\)

\(\Leftrightarrow x=40\)

P/s tham khảo nha

a,\(7-\left(18+x\right)=-15\)

\(18+x=7-\left(-15\right)\)

\(18+x=22\)

\(x=4\)

b,\(\left(x-17\right)-\left(-3\right)=0\)

\(x-17=-3\)

\(x=14\)

c,\(-18-\left(x-6\right)=0\)

\(x-6=-18\)

\(x=-12\)

d,\(29-\left(10+29\right)=x-\left(27-9\right)\)

\(x-18=-10\)

\(x=8\)

a) \(7-\left(18+x\right)=-15\)

\(\Leftrightarrow18+x=7+15\)

\(\Leftrightarrow18+x=22\)

\(\Leftrightarrow x=22-18\)

\(\Leftrightarrow x=4\)

b) \(\left(x-17\right)-\left(-3\right)=0\)

\(\Leftrightarrow\left(x-17\right)+3=0\)

\(\Leftrightarrow x-17=0-3\)

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

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

\(\Leftrightarrow x=14\)

c) \(-18-\left(x-6\right)=0\)

\(\Leftrightarrow x-6=0+\left(-18\right)\)

\(\Leftrightarrow x-6=-18\)

\(\Leftrightarrow x=-18+6\)

\(\Leftrightarrow x=-12\)

d) \(29-\left(10+29\right)=x-\left(27-9\right)\)

\(\Leftrightarrow29-10-29=x-27+9\)

\(\Leftrightarrow-10=x-27+9\)

\(\Leftrightarrow x-27=-10-9\)

\(\Leftrightarrow x-27=-19\)

\(\Leftrightarrow x=-19+27\)

\(\Leftrightarrow x=8\)

a)
7 - (18 + x) = -15
18 + x = 7 - ( -15 )
18 + x = 7 + 15
18 + x = 22
x = 22 - 18
x = 4
b)
(x - 17) - (-3) = 0
x - 17 = 0 + -3
x - 17 = -3
x = -3 + 17
x = 14
c)
-18 - (x - 6) = 0
x - 6 = -18 - 0
x - 6 = -18
x = -18 + 6
x = -12
d)
29 - (10 + 29) = x - (27 - 9)
29 - 39 = x - 18
x - 18 = -10
x = -10 + 18
x = 8

a,\(2x+12-18=x+4-18\)

\(\Rightarrow2x-x=4-1+18-12\)

\(\Rightarrow x=9\)

b,\(-5x+10-102=-6x-102\)

\(\Rightarrow-5x+6x=-102+102-10\)

\(\Rightarrow x=-10\)

a, 2x + 12 - 18 = x + 4 - 18

    2x -x           = 4 - 18 - 12 + 18

     x               =  - 8

b, - 5x + 10 - 102 = - 6x - 102

    - 5x + 6x         = -102 - 10 + 102

        x                = - 10

VERY GOOD!!!

Ta có :

a. -23-x=15

→x=-23-15

→x=-38

b. -18-(x-25)=-5

→(x-25)=-18-(-5)

→x-25=-13

→x=-13+25

→x=12

mình làm hai câu một nhé

c. 36-(27-x)=63-x

→36-27+x=63-x

→9+x=63-x

→x+x=63-9

→2x=54

→x=27

a)(-25)+15+x=50

(-10)+x=50

x=50-(-10)

x=50+10

x=60

b)(-25)+15+x=-35

(-10)+x=-35

x=(-35)-(-10)

x=(-35)+10

x=-25

c)(-25)+15+x=-10

(-10)+x=-10

x=-10-(-10)

x=-10+10

x=0

dễ tick mik đi rồi giải cho mik thề

a) x = 50 + 25 - 15 = 60

b) x = -35 + 25 - 15 = -25

c) x = -10 + 25 - 15 = 0

x-(17-8) = 5+(10-3x)

x-9=5+10-3x

x+3x=5+10+9

x+3x=24

4x=24

x=24/4

x=6

vậy x=6

|x+1|=x+1 hoac |x+1|=-(x+1)                                                                                                                                                                     Voi |x+1|=x+1 ta co:|x+1|=a=>x+1=a=>x=a-1                                                                                                                                         Voi |x+1|=-(x+1) ta co:|x+1|=a=>-(x+1)=a=>-x-1=a=>-x=a+1=>-(-x)=-(a+1)=>x=-a-1 Vay x=a-1 hoac x=-a-1 nho ****