K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

24 tháng 3 2017

\(\frac{17}{2}\)\(\frac{3}{5}\)\(\frac{1}{2}\) x \(\frac{3}{5}\)\(\frac{3}{5}\)

\(\frac{51}{10}\)\(\frac{3}{10}\)\(\frac{3}{5}\)

\(\frac{27}{5}\)\(\frac{3}{5}\)

\(6\)

= 6 tk m nhé

4 tháng 7 2017

bài 1:

\(\frac{6}{11}+\frac{1}{3}+\frac{5}{11}\)

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

\(=\frac{11}{11}+\frac{1}{3}=1+\frac{1}{3}=\frac{3}{3}+\frac{1}{3}=\frac{4}{3}\)

bài 2:

\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}\)

\(=\left(\frac{1}{2}+\frac{1}{20}\right)+\left(\frac{1}{6}+\frac{1}{12}\right)\)

\(=\frac{11}{20}+\frac{1}{4}=\frac{11}{20}+\frac{5}{20}=\frac{15}{20}=\frac{3}{4}\)

bài 3: 

a) \(\frac{3}{2}\cdot\frac{4}{5}\cdot\frac{2}{3}=\left(\frac{3}{2}\cdot\frac{2}{3}\right)\cdot\frac{4}{5}=1\cdot\frac{4}{5}=\frac{4}{5}\)

b) \(\frac{6}{7}\cdot\frac{5}{3}\cdot\frac{7}{6}=\left(\frac{6}{7}\cdot\frac{7}{6}\right)\cdot\frac{5}{3}=1\cdot\frac{5}{3}=\frac{5}{3}\)

bài 4: 

a) \(\frac{2}{5}\cdot\frac{1}{4}+\frac{3}{4}\cdot\frac{2}{5}=\frac{2}{5}\cdot\left(\frac{1}{4}+\frac{3}{4}\right)=\frac{2}{5}\cdot1=\frac{2}{5}\)

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

4 tháng 7 2017

Bài 1: 

  6/11 + 1/3 + 5/11 

= ( 6/11 + 5/11) + 1/3

= 11/11 + 1/3

= 1 + 1/3 

= 3/3 +1/3  

= 4/3 

Bài 2: 

1/2 + 1/6 + 1/12 + 1/20 

= ( 1/2 + 1/6 + 1/12 ) + 1/20 

= ( 6/12 + 2/12 + 1/12 ) + 1/20 

=9/12 + 1/20 

= 3/4 +1/20  

= 15/20 + 1/20 

= 16/20 = 4/5

 Bài 3:

a) \(\frac{3}{2}\times\frac{4}{5}\times\frac{2}{3}\) \(=\left(\frac{3}{2}\times\frac{2}{3}\right)\times\frac{4}{5}\)\(=1\times\frac{4}{5}=\frac{4}{5}\) 

b)  \(\frac{6}{7}\times\left(\frac{5}{3}\times\frac{7}{6}\right)\) \(=\frac{6}{7}\times\frac{35}{18}\)\(=\frac{1\times5}{7\times3}=\frac{5}{21}\)   

Bài 4:

a) 2/5  x 1/4 + 3/4 x 2/5 

= 2/5 x ( 1/4  + 3/4) 

 = 2/5 x  1 

= 2/5

 b) 6/11 : 2/3 +5/11 : 2/3 

=  ( 6/11 + 5/11) x 3/2 

= 11/11 x 3/2  

= 1 x 3/2  

=  3/2  

....  

4 tháng 3 2016

a) \(\frac{16}{35}+\frac{8}{35}=\frac{24}{35}\)

b)\(\frac{160}{77}-\frac{28}{77}=\frac{132}{77}=\frac{12}{1}=12\)

c)\(\frac{72}{180}=\frac{18}{45}\)

d) \(\frac{90}{360}=\frac{1}{4}\)

17 tháng 3 2017

1/8 x 5/6 + 5/6 x 2/3

= (1/8 + 2/3) x 5/6

= 95/144

1/8 x 5/6 + 5/6 x 2/3

= 5/48 +5/9

= 95/144

17 tháng 3 2017

\(\frac{1}{8}\times\frac{5}{6}+\frac{5}{6}\times\frac{2}{3}\)

\(=\frac{5}{6}\times\left(\frac{1}{8}+\frac{2}{3}\right)\)

\(=\frac{5}{6}\times\frac{19}{24}\)

\(=\frac{99}{144}\)

9 tháng 3 2016

a) 1/2x4/3:6/5

=2/3:6/5

=5/9
b)1/2:4/3x6/5

=3/8x6/5

=9/20

lưu ý / là gạch phân số

9 tháng 3 2016

a) 4/6:6/5=5/9

b) 3/8x6/5=9/20

9 tháng 6 2018

a)  \(4\frac{3}{8}+5\frac{2}{3}=4+\frac{3}{8}+5+\frac{2}{3}\)

\(=\left(4+5\right)+\left(\frac{3}{8}+\frac{2}{3}\right)\)

\(=9+\frac{25}{24}=9+1\frac{1}{24}=9+1+\frac{1}{24}\)

\(=10+\frac{1}{24}=10\frac{1}{24}\)

b )  \(\frac{5}{2}\cdot\frac{1}{3}+\frac{1}{4}=\frac{5}{6}+\frac{1}{4}=\frac{13}{12}=1\frac{1}{12}\)

9 tháng 6 2018

a) 35/8+17/3= 105/24+135/24=241/24

b) 5/2*1/3+1/4= 5/6+1/4= 20/24+6/24=13/12

2 tháng 6 2017

\(\Rightarrow x\times\left(\frac{1}{2}+\frac{3}{2}\right)=\frac{4}{5}\)

\(\Rightarrow x\times\frac{4}{2}=\frac{4}{5}\)

\(\Rightarrow x\times2=\frac{4}{5}\)

\(\Rightarrow x=\frac{4}{5}\div2\)

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

\(\Rightarrow x=\frac{2}{5}\)

2 tháng 6 2017

\(x\times\frac{1}{2}+\frac{3}{2}\times x=\frac{4}{5}\)

\(x\times\left(\frac{1}{2}+\frac{3}{2}\right)=\frac{4}{5}\)

\(x\times2=\frac{4}{5}\)

\(x=\frac{4}{5}:2\)

\(x=\frac{2}{5}\)

8 tháng 5 2016

Câu 1:\(\frac{12}{23}\times\frac{9}{28}+\frac{11}{23}\times\frac{9}{28}\)

\(=\frac{9}{28}\times\left(\frac{12}{23}+\frac{11}{23}\right)\)

\(=\frac{9}{28}\times\frac{23}{23}\)

\(=\frac{9}{28}\times1\)

\(=\frac{9}{28}\)

Câu 2:

\(3+\frac{1}{9}+\frac{3}{9}+2+\frac{5}{9}+3+2\)

\(=\left(3+2+2+3\right)+\left(\frac{1}{9}+\frac{3}{9}+\frac{5}{9}\right)\)

\(=10+\frac{9}{9}\)

\(=10+1\)

\(=11\)

\(\frac{12}{23}x\frac{9}{28}+\frac{11}{23}x\frac{9}{28}=\)\(\left(\frac{12}{23}+\frac{11}{23}\right)x\frac{9}{28}\)\(=\) \(1x\frac{9}{28}=\frac{9}{28}\)

\(3+\frac{1}{9}+\frac{3}{9}+2+\frac{5}{9}+3+2\)\(=\) \(\left(\frac{1}{9}+\frac{3}{9}+\frac{5}{9}\right)+\left(3+2+3+2\right)\)\(=\) \(1+3+2+3+2=\)\(11\) 

  

28 tháng 8 2019

\(\frac{3}{5}+\frac{2}{7}=\frac{21}{35}+\frac{10}{35}=\frac{31}{35}\)

\(\frac{3}{9}-\frac{1}{5}=\frac{15}{45}-\frac{9}{45}=\frac{6}{45}\)

\(\frac{2}{5}\times\frac{3}{7}=\frac{6}{35}\)

\(\frac{4}{9}:\frac{2}{5}=\frac{4}{9}\times\frac{5}{2}=\frac{20}{18}\)

Trả lời 

\(\frac{3}{5}+\frac{2}{7}=\frac{21}{35}+\frac{10}{35}=\frac{31}{35}\)

\(\frac{3}{9}-\frac{1}{5}=\frac{15}{45}-\frac{9}{45}=\frac{6}{45}=\frac{2}{15}\)

\(\frac{2}{5}\times\frac{3}{7}=\frac{6}{35}\)

\(\frac{4}{9}:\frac{2}{5}=\frac{4}{9}\times\frac{5}{2}=\frac{20}{18}=\frac{10}{9}\)

Study well