313×1729)×2934(313×1729)×2934

=313×1729×2934=313×1729×2934

=3×17×2913×29×34=3×17×2913×29×34

=3×17×2913×29×2×17=3×17×2913×29×2×17

=313×2=313×2

=326=326

421×1933+2542×1933421×1933+2542×1933

=1933×(421+2542)=1933×(421+2542)

=1933×(842+2542)=1933×(842+2542)

=1933×3342=1933×3342

=19×3333×42=19×3333×42

=1942

a,-2x -(x-17)=34-(-x+25)

-2x-x+17=34+x-25

-3x+17=9+x

-3x-x=9-17

-4x=-8

-->4x=8

x=8:4

x=2

Vậy x=2

b,17-(16x-37)=2x+43

17-16x+37=2x+43

20-16x=2x+43

-16x-2x=43-20

-18x=23

x=23:(-18)

x=23/-18

Mà x là số nguyên nên --> x thuộc tập rỗng

c,-2x-3.(x-17)=34-2(-x+25)

-2x-3x+51=34-2.(-x)-25

-5x+51=9-(-2).x

-5x+(-2).x=9-51

-7x=-42

7x=42

x=42:7

x=6

Vậy x=6

a,=3/13.17/29.29/34

=3/13.1/2

=3/26

b,=(4/21+25/42).19/33

=11/14.19/33

=19/42

`a, = 3/13 xx (17/29 xx 29/34)`

`= 3/13 xx 1/2`

`= 3/26`.

`b, = 19/33(4/21 + 25/42)`

`= 19/33 xx ( 33/42 )`

`= 19/42`

`a)(3/13xx17/29)xx29/34=3/13xx17/29xx29/34=[3xx17xx29]/[13xx19xx17xx2]=3/26`

`b)4/21xx19/33+25/42xx19/33=19/33xx(4/21+25/42)=19/33xx(8/42+25/42)=19/33xx33/42=19/42`

a. 8 x 37 x 5 x 25 = (8 x 25) x 37 x 5

                             = 200 x 5 x 37 = 1000 x 37 = 37000

b. 48 x 34 + 6 x 66 x 8 = 48 x 34 + 48 x 66 = 48 x ( 34 + 66) = 48 x 100 = 4800

c. 17 x (13 - 5) + 17 x 5 = 17 x 8 + 17 x 5 = 17 x (8 + 5) = 17 x 13 = 221

d. 78 x 100 - 100 = 78 x 100 - 100 x 1 = 100(78 - 1) = 100 x 77 = 7700

e. 6 x 17 x 8 + 3 x 37 x 16 + 4 x 46 x 12

= 48 x 17 + 48 x 37 + 48 x 46

= 48 x (17 + 37 + 46)

= 48 x 100 = 4800

f. 47 x 43 + 47 x 73 - 8 x 47 x 2 = 47 x 43 + 47 x 73 - 47 x 16 = 47 x (43 + 73 - 16) = 47 x 100 = 4700

8×37×5×25=296×5×25=1480×25=37000

48×34+6×66×8=1632+396×8=1632+3168=4800

15×(13-7)+17×5=15×6+17×5=90+85=175

78×100-100=7800-100=7700

a) \(\dfrac{25}{37}\times\dfrac{18}{29}+\dfrac{18}{29}\times\dfrac{12}{37}\)

\(=\dfrac{18}{29}\times\left(\dfrac{25}{37}+\dfrac{12}{37}\right)\)

\(=\dfrac{18}{29}\times\dfrac{37}{37}\)

\(=\dfrac{18}{29}\times1\)

\(=\dfrac{18}{29}\)

b) \(\dfrac{31}{85}\times\dfrac{11}{19}+\dfrac{31}{85}\times\dfrac{12}{19}-\dfrac{42}{19}\times\dfrac{31}{85}\)

\(=\dfrac{31}{85}\times\left(\dfrac{11}{19}+\dfrac{12}{19}-\dfrac{42}{19}\right)\)

\(=\dfrac{31}{85}\times\dfrac{-19}{19}\)

\(=\dfrac{31}{85}\times-1\)

\(=-\dfrac{31}{85}\)

c) \(\dfrac{16}{53}:\dfrac{17}{9}-\dfrac{16}{53}:\dfrac{17}{8}\)

\(=\dfrac{16}{53}:\left(\dfrac{9}{17}-\dfrac{8}{17}\right)\)

\(=\dfrac{16}{53}:\dfrac{1}{17}\)

\(=\dfrac{16}{901}\)

c) \(\dfrac{1}{5}\times\dfrac{12}{31}\times\dfrac{4}{3}+\dfrac{19}{31}\times\dfrac{4}{15}\)

\(=\dfrac{4}{15}\times\dfrac{12}{31}+\dfrac{19}{31}\times\dfrac{4}{15}\)

\(=\dfrac{4}{15}\times\left(\dfrac{12}{31}+\dfrac{19}{31}\right)\)

\(=\dfrac{4}{15}\times\dfrac{31}{31}\)

\(=\dfrac{4}{15}\times1\)

\(=\dfrac{4}{15}\)

a: =18/29*(25/37+12/37)

=18/29

b: =31/85(11/19+12/19-42/19)

=-31/85

c; =16/53(9/17+8/17)=16/53

d: =4/15(12/31+19/31)=4/15

a)x=37

b)x=-28

c)x=-48

d)x=15

a. \(158-x=-12\)

\(x=158+12\)

\(x=170\)

b. \(37+x=12\)

\(x=12-37\)

\(x=-25\)

c. \(2x-15=-47\)

\(2x=\left(-47\right)+15\)

\(x=\dfrac{\left(-32\right)}{2}\)

\(x=-16\)

d. \(\left(-5\right)^2-\left(5x-3\right)=43\)

\(25-\left(5x-3\right)=43\)

\(\left(5x-3\right)=25-43\)

\(5x=\left(-18\right)+3\)

\(x=\dfrac{\left(-15\right)}{5}=-3\)

e. \(\left|x-1\right|+\left(-5\right)=2\)

\(\left|x-1\right|=2-\left(-5\right)\)

\(\left|x-1\right|=7\)

\(\Leftrightarrow\left[{}\begin{matrix}x-1=7\\x-1=-7\end{matrix}\right.\Leftrightarrow}\left[{}\begin{matrix}x=8\\x=-6\end{matrix}\right.\)

f. \(\left|x+1\right|=4\)

\(\Leftrightarrow\left[{}\begin{matrix}x+1=4\\x+1=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-5\end{matrix}\right.\)

g. \(\left|x\right|=12\)

\(\Rightarrow x=\pm12\)

Câu h ko có x sao tìm

a) \(158-x=-12.\)

\(\Rightarrow x=158-\left(-12\right).\)

\(\Rightarrow x=158+12=170.\)

Vậy..........

b) \(37+x=12.\)

\(\Rightarrow x=12-37.\)

\(\Rightarrow x=-25.\)

Vậy..........

c) \(2x-15=-47.\)

\(\Rightarrow2x=-47+15.\)

\(\Rightarrow2x=-32.\)

\(\Rightarrow x=-\dfrac{32}{2}=-16.\)

Vậy..........

d) \(\left(-5\right)^2-\left(5x-3\right)=43.\)

\(\Rightarrow25-\left(5x-3\right)=43.\)

\(\Rightarrow5x-3=25-43.\)

\(\Rightarrow5x-3=-18.\)

\(\Rightarrow5x=-18+3.\)

\(\Rightarrow5x=-15.\)

\(\Rightarrow x=-\dfrac{15}{5}=3.\)

Vậy..........

e) \(\left|x-1\right|+\left(-5\right)=2.\)

\(\Rightarrow\left|x-1\right|=2-\left(-5\right).\)

\(\Rightarrow\left|x-1\right|=2+5.\)

\(\Rightarrow\left|x-1\right|=7.\)

\(\Leftrightarrow\left[{}\begin{matrix}x-1=7\\x-1=-7\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=8\\x=-6\end{matrix}\right..\)

Vậy..........

f) \(\left|x+1\right|=4\Leftrightarrow\left[{}\begin{matrix}x+1=4\\x+1=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-5\end{matrix}\right..\)

Vậy..........

g) \(\left|x\right|=12\Leftrightarrow\left[{}\begin{matrix}x=12\\x=-12\end{matrix}\right..\)

Vậy..........

a: =>15/5*34/17<x<120/15

=>6<x<8

=>x=7

b; =>20/5*58/29<x<112/11

=>8<x<112/11

=>x=9 hoặc x=10

a) -2x-x+17=34+x-25

<=> -2x-x-x=34-25-17

<=> -4x=-8

<=> x=2

b)17x+16x+37=2x+43

<=> 33x-2x=43-37

<=> 31x=6

<=>x=\(\frac{6}{31}\)

c) -2x-3x+51=34+2x-50

<=>-5x-2x=34-50-51

<=>-7x=-67

<=>x=\(\frac{67}{7}\)

d) [-2.(4x²-4x+1)- 1]=-106

<=> -8x²+8x-2-1=-106

<=>-8x²+8x=-103

nhớ ghi cách làm ra nha !