4/7 *1/3+5/7:2/3

\(\frac{4}{21}\)+ \(\frac{15}{14}\)= \(\frac{53}{42}\)

=4/21+15/14

=53/42

10/29+11/29+12/29+...+19/29

=10+11+12+13+14+15+=16+17+18+19/29

=145/29

9/8 - 1/3 x 3/4 

=9/8 - 1/4

=7/8

chúc bạn học tốt nha

9 / 8 - 1/3 x 3/4 = 27 / 24 - 8 / 24 x 3/4 = 21 / 24 x 3/4 =  7/8 x 3/4 = 21 /32 

CÓ VẺ LÀ HƠI KHÓ HỈ CẬU Ạ

\(2\times\frac{2}{4}\div\frac{4}{5}\)

\(\Rightarrow\frac{2}{1}\times\frac{2}{4}\div\frac{4}{5}\)

\(\Rightarrow\frac{4}{4}\div\frac{4}{5}\)

\(\Rightarrow\frac{4}{4}\times\frac{5}{4}\)

\(\Rightarrow\frac{5}{4}\)

1. 

= 10 000 - 29 x 11

= 10 000 - 319

= 9681

2.

= ( 3/7 + 4/7 ) + ( 4/9 + 5/9 )

= 1 + 1

= 2

a, `5/7 +4/5 -x =9/7`

`4/5 -x =9/7-5/7`

`4/5-x=4/7`

`x=4/5-4/7`

`x=8/35`

b,`5/6:5xx2/5=5/6xx1/5xx2/5=1/15`

\(\left(\dfrac{6}{11}+\dfrac{5}{11}\right)\times\dfrac{3}{7}=\dfrac{11}{11}\times\dfrac{3}{7}=1\times\dfrac{3}{7}=\dfrac{3}{7}\)

\(\dfrac{3}{5}\left(\dfrac{7}{9}-\dfrac{2}{9}\right)=\dfrac{3}{5}\times\dfrac{5}{9}=\dfrac{1}{3}\)

`( 6 / 11 + 5 / 11 ) xx 3 / 7 = 11 / 11 xx 3 / 7 = 1 xx 3 / 7 = 3 / 7`

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`3 / 5 xx 7 / 9 - 3 / 5 xx 2 / 9 = 3 / 5 xx ( 7 / 9 - 2 / 9 ) = 3 / 5 xx 5 / 9 = 1 / 3`