a.125 x 3,75 x 0,08 x 2 = 125 x 0,08 x 2 x 3,75

= 10 x 2 x 3,75

= 20 x 3,75

= 75

125×3,75×0,08×2

=(125×0,08)×(3,75×2)

=10×7,5

=75

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

`5/9 : 4/7 + 13/9 xx 7/4`

`= 5/9 xx 7/4 + 13/9 xx 7/4`

`= ( 5/9 + 13/9 ) xx 7/4`

`= 18/9 xx 7/4`

`= 2 xx 7/4`

`=7/2` 

\(=\dfrac{5}{9}\times\dfrac{7}{4}+\dfrac{13}{9}\times\dfrac{7}{4}=\dfrac{7}{4}\times\left(\dfrac{5}{9}+\dfrac{13}{9}\right)=\dfrac{7}{4}\times2=\dfrac{14}{4}=\dfrac{7}{2}\)

\(=\dfrac{5}{9}\times\dfrac{7}{4}+\dfrac{13}{9}\times\dfrac{7}{4}=\dfrac{7}{4}\times\left(\dfrac{5}{9}+\dfrac{13}{9}\right)=\dfrac{7}{4}\times2=\dfrac{7}{2}\)

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

5/9 : 4/7 +13/9 *7/4

=(5/9+13/9)* (4/7:7/4)
=2/1+1/1

=3/1

=3

sửa hộ cái lớp cái !

`a: =(7/3-4/3)+11/5=16/5`

`b: =(18/13-5/13)+55/46=1+55/46=101/46`

`c: =27/25-4/9-2/25+5/9=(27/25-2/25)+(5/9-4/9)=1+1/9=10/9`

   35  x 20 x 5           8 x 9 x 125         25 x 7 x 4    72:(8x3)

= 35 x ( 20  x5 )      = ( 8x125) x 9    = (25x4)x7    = 72: 24

= 35 x 100              = 1 000 x 9       = 100x7        = 3

= 3 500                  = 9  000            =700

(36x7):4

=36: 4 x 7 

= 9 x7

= 63 

35 x 20 x 5 = 35\(\times\)(20 \(\times\)5)= 35 \(\times\)100=3500

8 \(\times\)9 \(\times\) 125 =(8\(\times\) 125)\(\times\)9=1000\(\times\)9=9000

25 \(\times\)7\(\times\)4=(25 \(\times\)4)\(\times\)7=100\(\times\)7=700

72 : (8\(\times\)3)=72 : 8 x 3 =(72:8) x 3=9 x   3=27

(36 x 7) : 4 =36 x 7 : 4 =7 x (36 :4)=7 x 9=63

\(a.14,52\div1,5-9,81\div1,5\)

\(=\left(14,52-9,81\right)\div1,5\)

\(=4,71\div1,5=3,14\)

\(b.\frac{5}{9}:\frac{4}{7}+\frac{13}{9}\times\frac{7}{4}\)

\(=\frac{5}{9}\times\frac{7}{4}+\frac{13}{9}\times\frac{7}{4}\)

\(=\left(\frac{5}{9}+\frac{13}{9}\right)\times\frac{7}{4}\)

\(=\frac{18}{9}\times\frac{7}{4}\)

\(=2\times\frac{7}{4}\)

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

14,52:1,5-9,81:1,5=( 14,52-9,81 ) : 1,5

=4,71:1,5

=3,14

con thứ 2 thì mình chịu, bạn tự làm nha.

học tốt lên nhé.  mình chỉ biết làm luôn thôi nhé.

a ) = ( 14,52 - 9,81 ) : 1,5

= 4,71 : 1,5 

= 3,14

b) = 5/9 * 7/4 + 13/9 * 7/4

    = ( 5/9+ 13/9 ) * 7/4

    =         2         * 7/4

    =          3,5 = 7/2

A  =\(\frac{2}{5}\times\frac{4}{7}+\frac{3}{5}\times\frac{4}{7}\)  B = \(\frac{17}{13}\times\frac{12}{17}-\frac{4}{13}\times\frac{12}{17}\)   C = \(\frac{9}{14}:\frac{6}{7}+\frac{5}{14}:\frac{6}{7}\)  D =\(\frac{9}{12}:\frac{7}{9}\times\frac{12}{19}\)

=  \(\frac{4}{7}\times\left(\frac{2}{5}+\frac{3}{5}\right)\)              =\(\left(\frac{17}{13}-\frac{4}{13}\right)\times\frac{12}{17}\)                = \((\frac{9}{14}+\frac{5}{14}):\frac{6}{7}\)         = \(\frac{9}{12}\times\frac{9}{7}\times\frac{12}{19}\)

=\(\frac{4}{7}\times1\)                                     = \(1\times\frac{12}{17}\)                                       = \(1:\frac{6}{7}\)                               = \(\frac{9\times9\times12}{12\times7\times19}\)

=\(\frac{4}{7}\)                                              =  \(\frac{12}{17}\)                                                =\(\frac{7}{6}\)                                    = \(\frac{9\times9}{7\times19}=\frac{81}{133}\)

   -  

`7/13+5/9+6/13+5/9`

`=(7/13+6/13)+(5/9+5/9)`

`=13/13+10/9`

`=1+10/9`

`=9/9+10/9`

`=19/9`

19/9