1) \(=\left(\frac{3}{5}+\frac{2}{5}\right).\frac{6}{11}\)

\(=1.\frac{6}{11}\)

\(=\frac{6}{11}\)

2)\(\frac{17}{25}.\left(\frac{11}{19}+\frac{6}{19}+\frac{2}{19}\right)\)

\(=\frac{17}{25}.1\)

\(=\frac{17}{25}\)

2.\(\frac{17}{25}.\frac{11}{19}+\frac{17}{25}.\frac{6}{19}+\frac{17}{25}.\frac{2}{19}=\frac{17}{25}\left(\frac{11}{19}+\frac{6}{19}+\frac{2}{19}\right)\\ =\frac{17}{25}.1\\ =\frac{17}{25}\)

`7/9+9/7+6/9+11/7`

`=(7/9+6/9)+(9/7+11/7)`

`=13/9+20/7`

rồi thuận tiện  nào cái bài này=)

= ( 7/9 + 6/9 ) + ( 9/7 + 11/7 ) 

= 13/9 + 20/7

= 271/63

1) 3/9 + 5/9 = 8/9

2) 1/2 x 2/3 x 3/4 x 4/5

= 1/5

(1-1/2)×(1-1/3)×(1-1/4)×(1-1/5)×1-1/6=1/2×2/3×3/4×4/5×5/6=1/6

1,

a,=4/7:4/9.3

=9/7.3

=27/7

b,=(7/11+4/11).5/6

=1.5/6

=5/6

`(6/7-2/7):4/9xx3=4/7xx9/4xx3=[4xx9xx3]/[7xx4]=27/7`

`7/11xx5/6+4/11xx5/6=(7/11+4/11)xx5/6=11/11xx5/6=5/6`

\(\dfrac{14}{9}\) x \(\dfrac{11}{8}-\dfrac{3}{8}\) x \(\dfrac{14}{9}\)

\(=\dfrac{14}{9}\) x \(\left(\dfrac{11}{8}-\dfrac{3}{8}\right)\)

\(=\dfrac{14}{9}\) x \(\dfrac{8}{8}=\dfrac{14}{9}\) x \(1\)

\(=\dfrac{14}{9}\)

oa cảm ơn bạn nhé :3

14/9 × 11/8 - 3/8 × 14/9 

= 14/9 × ( 11/8 - 3/8 ) 

= 14/9 × 8/8 

= 14/9 - 1 

= 5/9

\(\dfrac{9}{10}\times2+3\times\dfrac{9}{10}+\dfrac{9}{10}:\dfrac{1}{5}\)

\(=\dfrac{9}{10}\times2+\dfrac{9}{10}\times3+\dfrac{9}{10}\times5\)

\(=\dfrac{9}{10}\times\left(2+3+5\right)\)

\(=\dfrac{9}{10}\times10\)

\(=\dfrac{90}{10}\)

\(=9\)

\(\dfrac{9}{4}\times\dfrac{15}{11}+\dfrac{3}{4}:\dfrac{11}{7}-\dfrac{3}{4}\times\dfrac{8}{11}\)
\(=\dfrac{3}{4}\times3\times\dfrac{15}{11}+\dfrac{3}{4}\times\dfrac{7}{11}-\dfrac{3}{4}\times\dfrac{8}{11}\)
\(=\dfrac{3}{4}\times\dfrac{45}{11}+\dfrac{3}{4}\times\dfrac{7}{11}-\dfrac{3}{4}\times\dfrac{8}{11}\)
\(=\dfrac{3}{4}\times\left(\dfrac{45}{11}+\dfrac{7}{11}-\dfrac{8}{11}\right)\)
\(=\dfrac{3}{4}\times4\)
\(=3\)

`9/4xx15/11+3/4:11/7-3/4xx8/11`

`=3/4xx15/11xx3+3/4xx7/11-3/4xx8/11`

`=3/4xx45/11+3/4xx7/11-3/4xx8/11`

`=3/4xx(45/11+7/11-8/11)`

`=3/4xx4`

`=3`