\(=\left(\dfrac{3}{4}+\dfrac{1}{4}\right)+\left(\dfrac{2}{5}+\dfrac{3}{5}\right)=1+1=2\)

2

= 2

( 7/4+5/4) x 5/3= 12/4 x 5/3 = 3 x 5/3= 5

5

5

5x5x5-(5x5)

3/15 chia cả mẫu cả tử cho 3 được 1/5+2/5=3/5 nhé

`5/3 + 1/5 : 3/4`

`= 5/3 + 1/5 xx 4/3`

`= 5/3 + 4/15`

`= 25/15 +4/15`

`= 29/15`

5/3 + 1/5 : 3/4

= 5/3 + 1/5 x 4/3

= 5/3 + 4/15

= 25/15 + 4/15

=29/15

\(a.\dfrac{3}{4}\times\dfrac{5}{6}-\dfrac{1}{6}=\dfrac{5}{8}-\dfrac{1}{6}=\dfrac{11}{24}\)

\(b.\left(\dfrac{8}{9}+\dfrac{1}{3}\right):\dfrac{2}{5}=\dfrac{11}{9}:\dfrac{2}{5}=\dfrac{11}{9}\times\dfrac{5}{2}=\dfrac{55}{18}\)

a) \(\dfrac{3}{4}\times\dfrac{5}{6}-\dfrac{1}{6}=\dfrac{15}{24}-\dfrac{1}{6}=\dfrac{15}{24}-\dfrac{4}{24}=\dfrac{11}{24}\)

b) \(\left(\dfrac{8}{9}+\dfrac{1}{3}\right):\dfrac{2}{5}=\dfrac{11}{9}:\dfrac{2}{5}=\dfrac{11}{9}\times\dfrac{5}{2}=\dfrac{55}{18}\)

\(=\dfrac{2}{3}\times\left(\dfrac{4}{10}+\dfrac{1}{5}\right)\\ =\dfrac{2}{3}\times\dfrac{3}{5}=\dfrac{2}{5}\)

\(\dfrac{2}{3}\times\left(\dfrac{4}{10}+\dfrac{1}{5}\right)=\dfrac{2}{3}\times\left(\dfrac{4}{10}+\dfrac{2}{10}\right)=\dfrac{2}{3}\times\dfrac{6}{10}=\dfrac{2}{3}\times\dfrac{3}{5}=\dfrac{6}{15}=\dfrac{2}{5}\)

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