K
Khách

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

a) \(\dfrac{2}{3}+\dfrac{3}{5}=\dfrac{10}{15}+\dfrac{9}{15}=\dfrac{19}{15}\)

a) \(\dfrac{7}{12}-\dfrac{2}{7}+\dfrac{1}{12}=\dfrac{2}{3}-\dfrac{2}{7}=\dfrac{14}{21}-\dfrac{6}{21}=\dfrac{8}{21}\)

29 tháng 5 2022

a) \(\dfrac{-2}{3}+\dfrac{3}{4}=\dfrac{-8}{12}+\dfrac{9}{12}=\dfrac{1}{12}\)

b) \(\dfrac{5}{6}-\dfrac{-3}{5}=\dfrac{5}{6}+\dfrac{3}{5}=\dfrac{25}{30}+\dfrac{18}{30}=\dfrac{43}{30}\)

29 tháng 5 2022

`a)` \(\dfrac{-2}{3}+\dfrac{3}{4}=\dfrac{-8}{12}+\dfrac{9}{12}=\dfrac{1}{12}\)

`b)` \(\dfrac{5}{6}-\dfrac{-3}{5}=\dfrac{5}{6}+\dfrac{3}{5}=\dfrac{25}{30}+\dfrac{18}{30}=\dfrac{43}{30}\)

HQ
Hà Quang Minh
Giáo viên
27 tháng 11 2023

a)  $\frac{5}{2} \times \frac{4}{3} + \frac{1}{3} = \frac{{10}}{3} + \frac{1}{3} = \frac{{11}}{3}$

b) $\frac{7}{3} - \frac{2}{3}:\frac{5}{7} = \frac{7}{3} - \frac{2}{3} \times \frac{7}{5} = \frac{7}{3} - \frac{{14}}{{15}} = \frac{{35}}{{15}} - \frac{{14}}{{15}} = \frac{{21}}{{15}} = \frac{7}{5}$

c)  $\frac{3}{4} \times \left( {\frac{5}{2} - \frac{3}{2}} \right) = \frac{3}{4} \times 1 = \frac{3}{4}$

3 tháng 5 2022

2/5+5/12

=49/60

2/3-3/8

=7/24

3/7.4/9

=4/21

11/10-2/5:2/3

=11/10-3/5

=1/2

a: \(=\dfrac{13}{3}+\dfrac{17}{6}=\dfrac{26}{6}+\dfrac{17}{6}=\dfrac{43}{6}\)

b: \(=7-\dfrac{8}{3}=\dfrac{21-8}{3}=\dfrac{13}{3}\)

c: \(=\dfrac{17}{7}\cdot\dfrac{7}{4}=\dfrac{17}{4}\)

d: \(=\dfrac{16}{3}:\dfrac{16}{5}=\dfrac{16}{3}\cdot\dfrac{5}{16}=\dfrac{5}{3}\)

HQ
Hà Quang Minh
Giáo viên
5 tháng 10 2023

a) \(\dfrac{3}{5} - \dfrac{{ - 1}}{3}\)

\( = \dfrac{{3.3}}{{5.3}} - \dfrac{{ - 1.5}}{{3.5}}\)

\( = \dfrac{9}{{15}} - \dfrac{{ - 5}}{{15}} = \dfrac{{9 - \left( { - 5} \right)}}{{15}} = \dfrac{{14}}{{15}}\)

b) \( - 3 - \dfrac{2}{7}\)

\(\begin{array}{l} = \dfrac{{ - 3.7}}{{1.7}} - \dfrac{2}{7}\\ = \dfrac{{ - 21}}{7} - \dfrac{2}{7}\\ = \dfrac{{ - 21 - 2}}{7}\\ = \dfrac{{ - 23}}{7}\end{array}\)

24 tháng 4 2021

24 tháng 4 2021

\(\dfrac{3}{10}:\dfrac{2}{5}=\dfrac{3}{10}.\dfrac{5}{2}=\dfrac{15}{20}=\dfrac{3}{4}\)

\(\dfrac{4}{7}:\dfrac{3}{11}=\dfrac{4}{7}\dfrac{.11}{3}=\dfrac{44}{21}\)

a: \(=\dfrac{-7}{8}\left(\dfrac{3}{5}+\dfrac{2}{5}\right)+3+\dfrac{7}{8}=\dfrac{-7}{8}+\dfrac{7}{8}+3=3\)

b: \(=-\dfrac{8}{5}:\dfrac{5}{3}=-\dfrac{24}{25}\)

c: \(=\dfrac{6}{7}+\dfrac{1}{8}-\dfrac{3}{4}=\dfrac{6}{7}+\dfrac{1}{8}-\dfrac{6}{8}=\dfrac{6}{7}-\dfrac{5}{8}=\dfrac{48}{56}-\dfrac{35}{56}=\dfrac{13}{56}\)

 

HQ
Hà Quang Minh
Giáo viên
27 tháng 11 2023

a) $\frac{3}{2} \times \frac{5}{8} + \frac{7}{4} = \frac{{15}}{{16}} + \frac{7}{4} = \frac{{15}}{{16}} + \frac{{28}}{{16}} = \frac{{43}}{{16}}$

b) $\frac{8}{5}:\left( {\frac{4}{3} - \frac{5}{6}} \right) = \frac{8}{5}:\left( {\frac{8}{6} - \frac{5}{6}} \right) = \frac{8}{5}:\frac{1}{2} = \frac{8}{5} \times 2 = \frac{{16}}{5}$

c) $\frac{3}{4} \times \frac{1}{5} - \frac{1}{{10}} = \frac{3}{{20}} - \frac{1}{{10}} = \frac{3}{{20}} - \frac{2}{{20}} = \frac{1}{{20}}$

11 tháng 11 2021

a)= 6/5 : 3/4 = 6/5 . 4/3 = 24/15 
b) 2 - ( 3/6 + 5/6 ) = 2 - 8/6 = 2 - 4/3 = 2/1 - 4/3 = 6/3 - 4/3 = 2/3

10 tháng 5 2022

a) \(\dfrac{11}{10}+\dfrac{3}{5}:\dfrac{2}{3}=\dfrac{11}{10}+\dfrac{3}{5}\times\dfrac{3}{2}=\dfrac{11}{10}+\dfrac{9}{10}=\dfrac{20}{10}=2\)

b) \(\dfrac{4}{3}+5\times\dfrac{5}{8}=\dfrac{4}{3}+\dfrac{25}{8}=\dfrac{32}{24}+\dfrac{75}{24}=\dfrac{107}{24}\)

c) \(\left(\dfrac{2}{5}+\dfrac{3}{7}\right)\times\dfrac{25}{29}=\left(\dfrac{14}{35}+\dfrac{15}{35}\right)\times\dfrac{25}{39}=\dfrac{29}{35}\times\dfrac{25}{39}=\dfrac{145}{274}\)

d) \(\dfrac{1}{4}\times\dfrac{5}{12}+\dfrac{5}{12}\times\dfrac{4}{5}=\dfrac{5}{12}\times\left(\dfrac{1}{4}+\dfrac{4}{5}\right)=\dfrac{5}{12}\times\dfrac{21}{20}=\dfrac{105}{240}=\dfrac{7}{16}\)

10 tháng 5 2022

a) \(\dfrac{11}{10}+\dfrac{3}{5}x\dfrac{3}{2}=\dfrac{11}{10}+\dfrac{9}{10}=\dfrac{20}{10}=2\)

b) \(\dfrac{4}{3}+\dfrac{25}{8}=\dfrac{32}{24}+\dfrac{75}{24}=\dfrac{107}{24}\)

c) \(\dfrac{29}{35}x\dfrac{25}{29}=\dfrac{5}{7}\)

\(=\dfrac{5}{12}x\left(\dfrac{1}{4}+\dfrac{4}{5}\right)=\dfrac{5}{12}x\dfrac{21}{20}=\dfrac{7}{16}\)