a)\(\frac{2}{3}:\frac{4}{9}+\frac{1}{3}:\frac{4}{9}\)

=\(\frac{4}{9}:\left(\frac{2}{3}+\frac{1}{3}\right)\)

=\(\frac{4}{9}:1=\frac{4}{9}\)

b

a 9/4

b 49/40

c 36/35

d 144/441

\(a,4\frac{5}{9}:\frac{\left(-5\right)}{7}+\frac{4}{9}:\frac{-5}{7}\)

\(=\frac{41}{9}.\frac{-7}{5}+\frac{4}{9}.\frac{-7}{5}\)

\(=\frac{-7}{5}.\left(\frac{41}{9}+\frac{4}{9}\right)\)

\(=-\frac{7}{9}.5\)

\(=-7\)

a)Bn Kaito Kid làm rùi!

B)Không viết lại đề

\(=\frac{11}{7}\cdot\left(-\frac{3}{5}+\frac{4}{9}-\frac{2}{5}+\frac{5}{9}\right)=\frac{11}{7}\cdot0=0\)

c)Không viết lại đề

\(A=\left(2+4+...+100\right)\left(\frac{3}{5}\cdot\frac{10}{7}-\frac{6}{7}\right):\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{100}\right)\)

\(=\left(2+4+6+...+100\right)\cdot0\cdot\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{100}\right)=0\)

\(=\frac{7}{6}\cdot\left(\frac{3}{26}-\frac{3}{13}+\frac{1}{10}-\frac{8}{5}\right)=\frac{7}{6}\left(\frac{-3}{26}+\frac{-17}{10}\right)=\frac{7}{6}\cdot\frac{236}{130}=\frac{413}{195}\)

D)

Dòng trên chữ D) là phần c)

Dưới phần c) là phần d) nha!(Lỗi đánh máy)

a= (\(\frac{2}{5}\)+\(\frac{2}{9}\)+\(\frac{2}{11}\)\(\times\)\(\frac{5}{7}\)\(+\frac{7}{9}\)\(+\frac{7}{11}\)\()\)

Bài 2: 

a: =>x/7=1/21

=>x=1/3

c: =>x(3x-2)=0

=>x=0 hoặc x=2/3

Bài1:

a: \(=\left(-\dfrac{7}{3}\right)^{3-2}=\dfrac{-7}{3}\)

b: \(=\left(-\dfrac{4}{9}\right)^{1-3}=\left(-\dfrac{4}{9}\right)^{-2}=\dfrac{81}{16}\)

c: \(=\left(\dfrac{1}{5}\right)^{10-7}=\left(\dfrac{1}{5}\right)^3=\dfrac{1}{125}\)

(7x6=5+2+6x7) =

A=\([\)\(\frac{2}{7}\)\(\times\)(\(\frac{1}{4}-\frac{1}{3}\))\(]\)\(\div\)\([\)(\(\frac{2}{7}\times\)(\(\frac{3}{9}-\frac{2}{5}\))\(]\)
  =(\(\frac{2}{7}\times\)\(\frac{-1}{12}\))\(\div(\)\(\frac{2}{7}\times\)\(\frac{-1}{15}\))
=\(\frac{-1}{42}\)\(\div\)\(\frac{-2}{35}\)
=\(\frac{-1}{42}\)\(\times\)\(\frac{35}{-2}\)
=\(\frac{5}{12}\)

ta có:4/5:(4/5*5/4)/16/25-1/25+(27/25-2/25):4/7/(59/9-13/4)*36/17+6/5*1/2

       =4/5:3/5+7/4:7+3/5

        =4/3+1/4+3/5

         =3/2+3/5=21/10

giải hộ milk nha