a) 131 – (45 + 17) = 131 – 62 = 69

b) 71 – (58 – 33) = 71 – 25 = 46

c) (77 + 48) : 5 = 125 : 5 = 25

d) 56 : (4 x 2) = 56 : 8 = 7

a) 131 - ( 45 + 17 ) = 131 - 62 =  69

b) 71 - ( 58 - 33 ) = 71 - 25 = 46

c) ( 77 + 48 ) : 5 = 125 : 5 = 25

d) 56 : ( 4 x 2 ) = 56 : 8 = 7

a: x-56:4=16

nên x-14=16

hay x=30

b: \(101+\left(36-4x\right)=105\)

\(\Leftrightarrow36-4x=4\)

hay x=8

Vì a: x-56:4=16

    =>x-14=16

   Hay:x=30

Vì b: 

   Hay:x=8

         Vậy x={30:8}

 Nếu sai thì thui nhá,đừng chửi mình!

Cách 1:

     \(\dfrac{3}{7}\) x \(\dfrac{16}{33}\) + \(\dfrac{16}{33}\) x \(\dfrac{4}{7}\)

=    \(\dfrac{48}{231}\) + \(\dfrac{64}{231}\)

= \(\dfrac{112}{231}\)

= \(\dfrac{16}{33}\)

cách 2:  \(\dfrac{3}{7}\) x \(\dfrac{16}{33}\) + \(\dfrac{16}{33}\) x \(\dfrac{4}{7}\)

       = \(\dfrac{16}{33}\) x ( \(\dfrac{3}{7}\) + \(\dfrac{4}{7}\))

      = \(\dfrac{16}{33}\) x \(\dfrac{7}{7}\)

     = \(\dfrac{16}{33}\)

9,3×6,7+3,3

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`

(55x32)/ (33x56)

= (5x4) / (3x7)

=20/21

Trả lời: 20/21

20/21

k tớ đi

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

33 x ( 17 - 5 ) - 17 x ( 33 - 5 )

= 33 x 17 - 33 x 5 - 17 x 33 + 17 x 5

= ( 33 x 17 - 33 x 17 ) - 33 x 5 + 17 x 5

= 0                            - 5 x ( 33 - 17 )

= -5 x 16

= -80

54 - 6 x ( 17 + 9 )

= 54 - 6 x 17 - 6 x 9

= 54 - 102 - 54

= ( 54 - 54 ) - 102

= 0 - 102 = -102

30

30

30