a) 0,5 x - \(\frac{2}{3}\)x = \(\frac{7}{12}\)

   x . ( 0,5 - \(\frac{2}{3}\)) = \(\frac{7}{12}\)

   x .  \(\frac{-1}{6}\)        = \(\frac{7}{12}\)

   x                         = \(\frac{7}{12}\): \(\frac{-1}{6}\)

   x                          = \(\frac{-7}{2}\)

b) x : \(\frac{25}{3}\)      = -25 

    x                     = -25 . \(\frac{25}{3}\)

     x                    = \(\frac{-625}{3}\)

c) 5,5 x = \(\frac{13}{15}\)

          x = \(\frac{13}{15}\): 5,5

           x = \(\frac{26}{165}\)

d) (\(\frac{3x}{7}\)+ 1 ) : ( -4) = \(\frac{-1}{28}\)

   ( \(\frac{3x}{7}\)+ 1 )           = \(\frac{-1}{28}\). ( -4)

 \(\frac{3x}{7}\)+ 1                 = \(\frac{1}{7}\)

 \(\frac{3x}{7}\)                       = \(\frac{1}{7}\)- 1

  \(\frac{3x}{7}\)                      = \(\frac{-6}{7}\)

=> x = -2

e) y + 30% y =  -1,3

   y + \(\frac{3}{10}\)y = -1,3

  y . ( 1 + \(\frac{3}{10}\)) = -1,3

y .       \(\frac{13}{10}\)     = -1,3

y                          = -1,3 : \(\frac{13}{10}\)

y                          = -1

g) y - 25% y = \(\frac{1}{2}\)

    y - \(\frac{1}{4}\)y = \(\frac{1}{2}\)

    y . ( 1 - \(\frac{1}{4}\)) = \(\frac{1}{2}\)

    y   . \(\frac{3}{4}\)  = \(\frac{1}{2}\)

     y                = \(\frac{1}{2}\): \(\frac{3}{4}\)

     y                  = \(\frac{2}{3}\)

ai tốt bụng thì tk cho mk nha, mk đg âm điểm đây huhu

1: x=3/4-1/2=3/4-2/4=1/4

2: x-1/5=2/11

=>x=2/11+1/5=21/55

3: x-5/6=16/42-8/56

=>x-5/6=8/21-4/28=5/21

=>x=5/21+5/6=15/14

4: x/5=5/6-19/30

=>x/5=25/30-19/30=6/30=1/5

=>x=1

5: =>|x|=1/3+1/4=7/12

=>x=7/12 hoặc x=-7/12

6: x=-1/2+3/4

=>x=3/4-1/2=1/4

11: x-(-6/12)=9/48

=>x+1/2=3/16

=>x=3/16-1/2=-5/16

1)x= 1/4

2)x= 2/11+ 1/5

   x= 21/55

3)x - 5/6 = 5/21

   x         = 5/21+5/6

   x         = 15/14

4)x/5 = 5/6 + -19/30

   x:5 = 1/5

   x    = 1/5.5

   x    = 1

5) |x| - 1/4 = 6/18

    |x|           = 6/18 - 1/4

    |x|            =7/12

⇒x= 7/12 hoặc -7/12

6)x = -1/2 +3/4

   x= 1/4

7) x/15 = 3/5 + -2/3

   x:15  = -1/15

  x        = -1/15. 15

  x        = -1

8)11/8 + 13/6 = 85/x  

       85/24      = 85/x

  ⇒      x           = 24

9) x - 7/8 = 13/12

   x          = 13/12 + 7/8

   x          = 47/24

10)x - -6/15 = 4/27  

     x            = 4/27 + (-6/15)

    x             = -34/135

11) -(-6/12)+x = 9/48

                    x= 9/48 - 6/12

                    x = -5/16

12) x - 4/6 = 5/25 + -7/15

      x -4/6  =  -4/15

     x           = -4/15 + 4/6

    x             = 2/5

bài2 \(x\times\dfrac{15}{16}-x\times\dfrac{4}{16}=2\) 

     \(x\times\dfrac{11}{16}=2\) 

     \(x=2:\dfrac{11}{16}\) 

    \(x=\dfrac{32}{11}\)

Bài 1 : 

 \(\dfrac{x}{16}\times\left(2017-1\right)=2\)

          \(\dfrac{x}{16}\times2016=2\)

                      \(\dfrac{x}{16}=\dfrac{2}{2016}\)

                         \(x=\dfrac{2}{2016}\times16\)

                         \(x=\dfrac{1}{63}\)

1- (5\(\dfrac{4}{9}\) +x+7\(\dfrac{7}{18}\)) : 15\(\dfrac{3}{4}\) = 0 

1- (\(\dfrac{49}{9}+x+\dfrac{133}{18}\)) : \(\dfrac{63}{4}=0\) 

 (\(\dfrac{49}{9}+\dfrac{133}{18}\)+\(x\) ) : \(\dfrac{63}{4}\) = 1 - 0 

       (\(\dfrac{77}{6}\) + \(x\) ) : \(\dfrac{63}{4}\) = 1

         \(\dfrac{77}{6}+x\)         = 1 x \(\dfrac{63}{4}\) 

          \(\dfrac{77}{6}\) + \(x\)          = \(\dfrac{63}{4}\)

                  \(x\)            = \(\dfrac{63}{4}\) - \(\dfrac{77}{6}\)

                  \(x=\) \(\dfrac{35}{12}\)

sao mà dễ vậy

\(x+\frac{2}{3}=2\frac{1}{2}\)

\(x+\frac{2}{3}=\frac{5}{2}\)

\(x=\frac{5}{2}-\frac{2}{3}\)

\(x=\frac{11}{6}\)

\(8,75.x+1,25.x=26,3\)

\(x.\left(8,75+1,25\right)=26,3\)

\(x.10=26,3\)

\(x=26,3\div10\)

\(x=2,63\)

\(x-4\frac{5}{6}=2\frac{1}{6}+\frac{5}{6}\)

\(x-\frac{29}{6}=3\)

\(x=\frac{47}{6}\)

\(5\frac{4}{5}+x-7\frac{7}{18}=15\frac{3}{4}\)

\(\frac{29}{5}+x-\frac{133}{18}=\frac{63}{4}\)

\(\frac{29}{5}+x=\frac{63}{4}+\frac{133}{18}\)

\(\frac{29}{5}+x=\frac{259}{8}\)

\(x=\frac{259}{8}-\frac{29}{5}\)

\(x=\frac{1063}{40}\)

a, 30,24 + 30,24 + 30,24 + 30,24 x 7 - 30,24 : 0,1

= 30,24 x 3 + 30,24 x 7 - 30,24 : 0,1

= 30,24 x 10 - 30,24 : 0,1

= 30,24 x 10 - 30,24 x 10

= 0

b, 2 giờ 30 phút x 8 + 2,5 giờ x 3 - 150 phút

= 2,5 giờ x 8 + 2,5 giờ x 3 - 150 phút

= 2,5 giờ x 8 + 2,5 giờ x 3 - 2,5 giờ

= 2,5 giờ x 10

= 25 giờ

c, 1/2 : 0,5 - 1/4 : 0,25 + 1/8 : 0,125 - 1/10 : 0,1

= 1/2 x 2 + 1/4 x 4 + 1/8 x 8 - 1/10 x 10

= 1 + 1 + 1 - 1

= 2 

=30,24(1+1+1+7-0,1)

=30,24x9,9

=299,376