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

`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` 

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

   \(\frac{7}{4}\times\frac{15}{7}+\frac{13}{7}\times\frac{9}{4}-\frac{2}{7}\)

\(=\left(\frac{7}{4}+\frac{9}{4}\right)\times\left(\frac{15}{7}+\frac{13}{7}\right)-\frac{2}{7}\)

\(=4\times4-\frac{2}{7}\)

\(=16-\frac{2}{7}\)

\(=\frac{112}{7}-\frac{2}{7}\)

\(=\frac{110}{7}\)

sửa hộ cái lớp cái !

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

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

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

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

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

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

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

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

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

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

4/9 x (3/5-1/5) +4/9 -7/5 x 4/9

= 4/9 x 2/5 + 4/9 x 1 - 4/9 x 7/5

= 4/9 x (2/5+1-7/5)

=4/9 x 0

=0.

tick mk nha

HT

4/9 x (3/5-1/5) +4/9 -7/5 x 4/9

= 4/9 x 2/5 + 4/9 x 1 - 4/9 x 7/5

= 4/9 x (2/5+1-7/5)

=4/9 x 0

=0.

`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`

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 =\(\frac{9}{12}:\frac{7}{9}\times\frac{12}{19}\)

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

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

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

   -  

\(\dfrac{8}{13}+\dfrac{4}{9}+\dfrac{1}{3}+\dfrac{5}{13}+3\)

\(=1+\dfrac{7}{9}+3\)

\(=4+\dfrac{7}{9}=\dfrac{43}{9}\)