x+126/216=204/216-24/216

=>x+126/216=108/216

=>x=108/216-126/216

=>x=-18/216

=>x=-1/12

a )    x + 7/12 = 17/18 - 1/9 

        x + 7/12 = 17/18 - 2/18 

        x + 7/12 = 5/18 

              x     = 5/18 - 7/12

              x     = 10/36 - 21/36  

              x     =    -11/36 

b )   29/30 - ( 13/23 + x ) = 7/69 

       29/30 - 13/23 - x      = 7/69 

       29/30 - 39/69 - x      = 7/69

                  29/30 - x      = 7/69 + 39/69 

                  29/30 - x      = 46/69 

                             x      = 29/30 - 46/69 

                             x      =  3/10 

c ) x + 1/4 - 1/3 = 7/46

     x + 3/12 - 4/12 = 7/46

     x + -1/12          = 7/46

              x            = 7/46 + 1/12

              x            = 65/276 

 Tk mình nha !!! Chúc học giỏi !!! 
Ai thấy đúng TK mình nhé !!!! 

Tìm x :

a) x + 7/12  = 17/18 - 1/9

    x + 7/12  =      15/18

    x             =   15/18 - 7/12

    x            =          31/36

mik nè

còn ý b nữa bn ơi 

a) x+7/12=17/18-1/9

x+7/12=17/18-2/18

x+7/12=15/18

       x=15/18 -7/12

       x=30/36 -21/36

        x=9/36 =1/4

b)29/30 -(13/23+x)=7/69

             (13/23+x)=29/30-7/69

             (13/23+x)=199/230

                        x=199/230-13/23

                        x=3/10

a) \(x+\frac{7}{12}=\frac{17}{18}-\frac{1}{9}\)

\(\Rightarrow x+\frac{7}{12}=\frac{5}{6}\)

\(\Rightarrow x=\frac{5}{6}-\frac{7}{12}\)

\(\Rightarrow x=\frac{1}{4}\)

b) \(\frac{29}{30}-\left(\frac{13}{23}+x\right)=\frac{7}{69}\)

\(\Rightarrow\frac{13}{23}+x=\frac{29}{30}-\frac{7}{69}\)

\(\Rightarrow\frac{13}{23}+x=\frac{199}{230}\)

\(\Rightarrow x=\frac{199}{230}-\frac{13}{23}\)

\(\Rightarrow x=\frac{3}{10}\)

a)\(x+\frac{7}{12}=\frac{17}{18}-\frac{1}{9}\)

\(x+\frac{7}{12}=\frac{5}{6}\)

\(x=\frac{5}{6}-\frac{7}{12}\)

\(x=\frac{1}{4}\)

b)\(\frac{29}{30}-\left(\frac{13}{23}+x\right)=\frac{7}{69}\)

\(\left(\frac{13}{23}+x\right)=\frac{29}{30}-\frac{7}{69}\)

\(\left(\frac{13}{23}+x\right)=\frac{199}{230}\)\(x=\frac{199}{230}-\frac{13}{23}\)

\(x=\frac{3}{10}\)

a.X+7/12=17/18-1/9

X+7/12=15/18

X=15/18-7/12

X=1/4

b.29/30-(13/23+X)=7/69

13/23+X=7/69+29/30

13/23+X=737/690

X=737/690-13/23

X=377/690

a x=1/4                                                       b x= 3/10

1) = 35 . 18 - 35 . 18 = 0

2) = 45 - 5 . 12 + 5 . 9 = 45 - 60 + 45 = 30

3) = 24 . 16 - 24 . 5 - 16 . 24 - 16 . 5

= (24 . 16 - 16 . 24) - 5 (24 - 16)

= 0 - 5 . 8 = 0 - 40 = -40

4) = 29 . 19 - 29 . 13 - 19 . 29 - 19 . 13

= (29 . 19 - 29 . 19) - 13 (29 - 19)

= 0 - 13 . 10 = 0 - 130 = -130

5) = 31 . (-18) + 31 . (-81) - 31 . 1

= 31 [(-18) + (-81) - 1]

= 31 . (-100) = -3100

6) = (-12) . 47 + (-12) . 52 + (-12). 1

= (-12) . (47 + 52 + 1)

= (-12) . 100 = -1200

7) = 13 . 45 - 3 . 45

= 45 (13 - 3)

= 45 . 10 = 450

8) = (-48) + 48 . (-78) + 48 . (-21)

= (-48) . 1 + 48 . (-78) + 48 . (-21)

= 48 . (-1) + 48 . (-78) + 48 . (-21)

= 48 . [(-1) + (-78) + (-21)]

= 48 . (-100) = -4800

1) 35x18-5x7x18

= 35x18-35x18

= 35x(18-18)

= 35x0=0

3) 24.(16-5)-16.(24-5)

= 24.16-24.5-16.24-16.5

=[24.16-16.24]-[24.5-16.5]

= [ 24. (16-16)]- [(24-16).5]

= [24.0]-[8.5]

= 0-40=-40

4) 29.(19-13)-19.(29-13)

=29.19-29.13-19.29-19.13

=[ 29.19-19.29]-[ 29.13-19.13]

= [ 29.(19-19)]-[(29-19).13]

=[29.0]-[10.13]

= 0-130= -130

5) 31.(-18)+31.(-81)-31

= 31.(-18)+31.(-81)-31.1

= 31.[(-18)+(-81)-1]

=31.(-100)

= -3100

6);7);8 tương tự 4);5);6)

1)x=-30

2)x=-81

3)x=4

4)x=62

5)x=6

6)-13

7)-13

8)-31

9)x=-6;0;6;12

tk minh nha

bạn không có lời giải

1

x + 7/12= 15/18

x= 15/18-7/12

x= 1/4

k mk nhé

3

4/10= 2/5

\(\frac{x}{15}\)=\(\frac{2}{5}\)

x= 15:5x2= 6

x= 6

k mk nhé