Là sao!!!!!???????!!!!!???

a: \(=\dfrac{4}{5}\cdot\dfrac{7}{3}\cdot\dfrac{3}{7}\cdot\dfrac{5}{4}+2011=2011+1=2012\)

b: \(=\dfrac{1}{3}\cdot\dfrac{9}{7}\cdot\dfrac{7}{9}=\dfrac{1}{3}\)

`a)4/5:3/7xx3/7:4/5+2011`

`=4/5xx7/3xx3/7xx5/4+2011`

`=(4/5xx5/4)xx(7/3xx3/7)+2011`

`=1xx1+2011`

`=1+2011`

`=2012`

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`b)1/2xx2/3:7/9xx7/9`

`=1/2xx2/3xx9/7xx7/9`

`=(1/2xx2/3)xx(9/7xx7/9)`

`=1/3xx1`

`=1/3`

TH1: \(A=\left(9-\frac35+\frac23\right)-\left(7+\frac75-\frac32\right)-\left(3-\frac95+\frac52\right)\)

\(=\left(\frac{135}{15}-\frac{9}{15}+\frac{10}{15}\right)-\left(\frac{70}{10}+\frac{14}{10}-\frac{15}{10}\right)-\left(\frac{30}{10}-\frac{18}{10}+\frac{25}{10}\right)\)

\(=\frac{136}{15}-\frac{69}{10}-\frac{37}{10}=\frac{136}{15}-\frac{106}{10}=\frac{272}{30}-\frac{318}{30}=-\frac{46}{30}=-\frac{23}{15}\)

TH2: \(A=\left(9-\frac35+\frac23\right)-\left(7+\frac75-\frac32\right)-\left(3-\frac95+\frac52\right)\)

\(=9-\frac35+\frac23-7-\frac75+\frac32-3+\frac95-\frac52\)

\(=\left(9-7-3\right)+\left(-\frac35-\frac75+\frac95\right)+\left(\frac32-\frac52\right)+\frac23=-1-\frac15-1+\frac23\)

\(=-2-\frac15+\frac23=-\frac{30}{15}-\frac{3}{15}+\frac{10}{15}=-\frac{23}{15}\)

1&2/3 là gì zậy ta =)?

1 và 2/3 nhé

Chọn A

\(a,\left(-\dfrac{4}{9}\right)\times\dfrac{3}{8}+\dfrac{1}{18}=-\dfrac{1}{6}+\dfrac{1}{18}=\dfrac{-1.3}{6.3}+\dfrac{1}{18}=\dfrac{-3+1}{18}=-\dfrac{2}{18}=-\dfrac{1}{9}\)

xem lại đề câu b

\(c,\left(\dfrac{1}{2}-\dfrac{2}{3}\right)\times\dfrac{4}{4}=\dfrac{1}{2}-\dfrac{2}{3}=\dfrac{3-4}{6}=-\dfrac{1}{6}\\ d,\dfrac{9}{7}\times\left(\dfrac{3}{7}-\dfrac{1}{2}\right)=\dfrac{9}{7}\times\left(\dfrac{3.2-7}{14}\right)=\dfrac{9}{7}\times\dfrac{-1}{14}=-\dfrac{9}{98}\)

a: \(=\dfrac{7\cdot5+3\cdot9}{45}\cdot\dfrac{2}{3}=\dfrac{62}{45}\cdot\dfrac{2}{3}=\dfrac{124}{135}\)

b: \(=\dfrac{6}{11}\cdot\dfrac{5}{7}=\dfrac{30}{77}\)

c: \(=\dfrac{7}{8}\cdot\dfrac{8-3}{9}=\dfrac{7}{8}\cdot\dfrac{5}{9}=\dfrac{35}{72}\)

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\(\text{#TNam}\)

`a, (7/9+3/5) \times 2/3`

`C1:`

`=62/45 \times 2/3`

`= 124/135`

`C2:`

`= 7/9 \times 2/3 + 3/5 \times 2/3`

`= 14/27 +2/5`

`= 124/135`

`b, `

`C1:`

`= 6/11 \times 5/7`

`=`30/77`

`C2:

`= 9/11 \times 5/7-3/11 \times 5/7`

`= 45/77 -15/77`

`= 30/77`

`c,`

`C1:`

`= 7/8 \times 5/9`

`=35/72`

`C2:`

`= 7/8 \times 8/9- 7/8 \times 1/3`

`= 7/9-7/24`

`=35/72`