a) \(4,9x+\frac{x}{10}=10,2\)

<=>49x+x=102

<=>50x=102

<=>x=102:50

<=>x=2,04

b)\(4,1x-\frac{x}{10}=2,4\)

<=>41x-x=24

<=>40x=24

<=>x=24:40

<=>x=0,6

nhanh nhất k nha bạn :))

a) X x 4,9 + X : 10 = 10,2

x (4,9 + 1/10) = 10,2

x* 5 = 10,2

x= 51/25

b) X x 4,1 - X : 10 = 2,4

x(4,1 - 1/10) =2,4

x* 4 = 2,4

x=3/5

X x4,9 + X x 0,1 =3,04

a)2,3:x+3,4:x=6

=>5,7/x=6

=>x=0,95

b)10,2:x+4,5:x=14

=>14,7:x=14

=>x=1,05

c)Xx4,9+x:10

=>49xX:10+x:10=102:10

=>50xX=102

=>x=2,04

d)4,1x-x:10=2,4

=>41x:10-x:10=24:10

=>40x=24

=>x=0,6

còn lại bạn tự làm nha mỏi tay quá

nhớ
 

a) 5,4 x 1,2 - 1,06 x4 + 15,2 x 2,5                         b) 8,3 x (6,25- 1,27): 0,25

= 6,48- 4,24 + 38                                                = (8,3 x 4,98) : 0,25

= 2,24 + 38                                                        = 41,334 : 0,25

= 40,24                                                             = 165,336

c) (34,08 - 41,2 x 0,75 ) x 10,2                          d) (31,02+ 1998x 0,01): 0,25

= 3,18 x 10,2                                                     = 51 : 0,25

= 32,436                                                          = 204

a) 240:x+118=178

240:x=178-118

240:x=60

x= 240:60

x= 4

b) 2/9 +x= 1

x= 1 -2/9

x=7/9

c) x* 6-4,08=2,28

x*6= 2,28 + 4,08

x*6= 6,36

x= 6,36: 6

x=1,06

d) x:4 -8,1=10,2

x:4 = 10,2 +8,1

x:4=18,3

x= 18,3 * 4

x=73,2

a) 240 : x + 118 = 178 

   240 : x            = 178 - 118 

   240 : x            = 60 

           x            = 240 : 60

           x            = 4 

a, 240 : x + 118 = 178 

    240 : x           = 178 - 118

    240 : x           =  60

                     x   =  240 : 60

                     x =   4 .

b, 2/9 + x = 1 

             x = 1 - 2/9

             x = 7/9

c, \(x\times6-4,08=2,28\)

     \(x\times6=2,28+4,08\)

     \(x\times6=6,36\)

     \(x=6,36\div6\)

     \(x=1,06\)

d, x : 4 - 8,1 = 10,2 

   x : 4           = 10,2 + 8,1

   x : 4           = 18,3

                 x  = 18,2 x 4 

                 x = 72,8 . 

Bạn thử lại nhé vì mk không chắc . hihi

CON điên vy ngu si tứ chi khó phát triển

bang 123456789 do ngu

a) \(2\dfrac{4}{9}+6\dfrac{7}{11}+7\dfrac{5}{9}+13\dfrac{4}{11}\)

\(=2+\dfrac{4}{9}+6+\dfrac{7}{11}+7+\dfrac{5}{9}+13+\dfrac{4}{11}\)

\(=\left(2+6+7+13\right)+\left(\dfrac{4}{9}+\dfrac{5}{9}\right)+\left(\dfrac{7}{11}+\dfrac{4}{11}\right)\)

\(=28+1+1\)

\(=30\)

b) \(\dfrac{3}{4}+\dfrac{1}{2}\times\dfrac{12}{5}-1\dfrac{1}{2}\)

\(=\dfrac{3}{4}+\dfrac{1}{2}-1-\dfrac{1}{2}\)

\(=\dfrac{3}{4}-1\)

\(=\dfrac{3}{4}-\dfrac{4}{4}\)

\(=-\dfrac{1}{4}\) 

`1/x + y/3 = 5/6`

`-> 1/x = 5/6 - y/3`

`-> 1/x = 5/6 - ( 2y ) / 6`

`-> 1/x = ( 5 - 2y ) / 6`

`-> x ( 5 - 2y ) = 6`

\(x,y\in Z\)

\(\dfrac{1}{x}+\dfrac{y}{3}=\dfrac{5}{6}\left(x\ne0\right)\)

\(\Rightarrow\dfrac{6}{6x}+\dfrac{2xy}{6x}=\dfrac{5x}{6x}\)

\(\Rightarrow6+2xy=5x\)

\(\Rightarrow5x-2xy=6\)

\(\Rightarrow x\left(5-2y\right)=6\)

\(\Rightarrow x=\dfrac{6}{5-2y}\left(y\ne\dfrac{5}{2}\right)\)

Vì x,y là các số nguyên nên:

\(6⋮\left(5-2y\right)\)

\(\Rightarrow5-2y\inƯ\left(6\right)\)

\(\Rightarrow5-2y\in\left\{1;2;3;6;-1;-2;-3;-6\right\}\)

\(\Rightarrow y\in\left\{2;1;3;4\right\}\)

*\(y=2\text{​​}\Rightarrow x=\dfrac{6}{5-2.2}=6\left(n\right)\)

\(y=1\text{​​}\Rightarrow x=\dfrac{6}{5-2.1}=2\left(n\right)\)

\(y=3\text{​​}\Rightarrow x=\dfrac{6}{5-2.3}=-6\left(n\right)\)

\(y=4\text{​​}\Rightarrow x=\dfrac{6}{5-2.4}=-2\left(n\right)\)

Vậy các cặp số x,y nguyên thỏa mãn (phương trình) là (6,2) ; (2,1) ; (-6,3) ; (-2,4).

1,27 x ( 7,5 - 2,5 +4) +1,25

= 1,27 x 9 +1,25

= 12,68

1,27 x ( 7,5 - 2,5 +4) +1,25

= 1,27 x 9 +1,25

= 12,68