Tính:a) $\dfrac{-7}{8}$ . $\dfrac{3}{5}$ - $\dfrac{2}{5}$ . $\dfrac{7}{8}$ $3\dfrac{7}{8}$b) -1,6 : ( 1 $\dfrac{2}{3}$ )c) $\dfrac{6}{7}$ $\dfrac{5}{8}$ : 5 - $\dfrac{3}{16}$ ....

Tính:a) $\dfrac{3}{8}+\dfrac{7}{8}$ b) $\dfrac{7}{9}-\dfrac{4}{9}$ c) $\dfrac{5}{6}+\dfrac{1}{8}$ d) $\dfrac{9}{15}-\dfrac{2}{5}$e) $\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{9}{5}$ g) $\dfrac{8}{10}-\dfrac{1}{10}-\dfrac{3}{10}$ ...

#Toán lớp 6

1

NL

Nguyễn Lê Phước Thịnh

4 tháng 3 2022

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

Đúng(2)

D

datcoder

CTVVIP

29 tháng 10 2023

1

NL

Nguyễn Lê Phước Thịnh

29 tháng 10 2023

a: $\dfrac{3}{8}+\dfrac{7}{8}=\dfrac{3+7}{8}=\dfrac{10}{8}=\dfrac{5}{4}$

b: $\dfrac{7}{9}-\dfrac{4}{9}=\dfrac{7-4}{9}=\dfrac{3}{9}=\dfrac{1}{3}$

c: $\dfrac{5}{6}+\dfrac{1}{8}=\dfrac{20}{24}+\dfrac{3}{24}=\dfrac{20+3}{24}=\dfrac{23}{24}$

d: $\dfrac{9}{15}-\dfrac{2}{5}=\dfrac{3}{5}-\dfrac{2}{5}=\dfrac{3-2}{5}=\dfrac{1}{5}$

e: $\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{9}{5}=\dfrac{2+3+9}{5}=\dfrac{14}{5}$

g: $\dfrac{8}{10}-\dfrac{1}{10}-\dfrac{3}{10}=\dfrac{8-1-3}{10}=\dfrac{4}{10}=\dfrac{2}{5}$

h: $\dfrac{23}{7}-\dfrac{4}{7}+\dfrac{2}{7}=\dfrac{23-4+2}{7}=\dfrac{21}{7}=3$

Đúng(1)

A

Aduvjp

20 tháng 12 2022

Tính:

a) $\sqrt{\dfrac{9}{16}}-\dfrac{5}{6}+\dfrac{3}{2}$ b) $\left(\dfrac{1}{9}+\dfrac{2}{3}\right)^2-\dfrac{5}{3}:\sqrt{25}$

c)$\dfrac{5}{11}.\left(-\dfrac{3}{7}\right)+\dfrac{5}{11}.\left(\dfrac{-5}{7}\right)+\left(-\dfrac{8}{7}\right).\dfrac{6}{11}$

d) $\dfrac{2^8.2^{18}}{8^5.4^6}$

#Toán lớp 7

1

NL

Nguyễn Lê Phước Thịnh

20 tháng 12 2022

a: $=\dfrac{3}{4}-\dfrac{5}{6}+\dfrac{3}{2}=\dfrac{9-10+18}{12}=\dfrac{17}{12}$

b: $=\left(\dfrac{1}{9}+\dfrac{6}{9}\right)^2-\dfrac{1}{3}=\dfrac{49}{81}-\dfrac{27}{81}=\dfrac{22}{81}$

c; $=\dfrac{5}{11}\left(-\dfrac{3}{7}-\dfrac{5}{7}\right)+\dfrac{-8}{7}\cdot\dfrac{6}{11}=\dfrac{-8}{7}\left(\dfrac{5}{11}+\dfrac{6}{11}\right)=-\dfrac{8}{7}$

d: $=\dfrac{2^{26}}{2^{15}\cdot2^{12}}=\dfrac{1}{2}$

Đúng(2)

QT

Quoc Tran Anh Le

Giáo viên

5 tháng 10 2023

Tính:

a)$\dfrac{6}{{13}}.\dfrac{8}{7}.\dfrac{{ - 26}}{3}.\dfrac{{ - 7}}{8}$

b) $\dfrac{6}{5}.\dfrac{3}{{13}} - \dfrac{6}{5}.\dfrac{{16}}{{13}}$

#Toán lớp 6

1

HQ

Hà Quang Minh

Giáo viên

5 tháng 10 2023

a) $\dfrac{6}{{13}}.\dfrac{8}{{7}}.\dfrac{{ - 26}}{3}.\dfrac{{ - 7}}{8}$

$\begin{array}{l} = \left( {\dfrac{6}{{13}}.\dfrac{{ - 26}}{3}} \right).\left( {\dfrac{8}{7}.\dfrac{{ - 7}}{8}} \right)\\ = \dfrac{{6.\left( { - 26} \right)}}{{13.3}}.\dfrac{{8.\left( { - 7} \right)}}{{7.8}}\\= (- 4).\left( { - 1} \right) = 4\end{array}$

b) $\dfrac{6}{5}.\dfrac{3}{{13}} - \dfrac{6}{5}.\dfrac{{16}}{{13}}$

$\begin{array}{l} = \dfrac{6}{5}.\left( {\dfrac{3}{{13}} - \dfrac{{16}}{{13}}} \right)\\ = \dfrac{6}{5}.\dfrac{{3 - 16}}{{13}}\\ = \dfrac{6}{5}.\dfrac{{-13}}{{13}}\\= \dfrac{6}{5}.\left( { - 1} \right)\\ = \dfrac{{ - 6}}{5}\end{array}$

NA

Ngoc Anh Thai

Giáo viên

31 tháng 8 2021

Tính:

a) $\dfrac{-1}{2}+\dfrac{5}{6}+\dfrac{1}{3}$;

b) $\dfrac{-3}{8}+\dfrac{7}{4}-\dfrac{1}{12}$;

c) $\dfrac{3}{5}:\left(\dfrac{1}{4}\cdot\dfrac{7}{5}\right)$;

d) $\dfrac{10}{11}+\dfrac{4}{11}:4-\dfrac{1}{8}$.

#Toán lớp 6

2

S

Shauna

31 tháng 8 2021

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Đúng(1)

NL

Nguyễn Lê Phước Thịnh

31 tháng 8 2021

a: $\dfrac{-1}{2}+\dfrac{5}{6}+\dfrac{1}{3}$

$=\dfrac{-3}{6}+\dfrac{5}{6}+\dfrac{2}{6}$

$=\dfrac{4}{6}=\dfrac{2}{3}$

b: $\dfrac{-3}{8}+\dfrac{7}{4}-\dfrac{1}{12}$

$=\dfrac{-9}{24}+\dfrac{42}{24}-\dfrac{2}{24}$

$=\dfrac{31}{24}$

c: $\dfrac{3}{5}:\left(\dfrac{1}{4}\cdot\dfrac{7}{5}\right)=\dfrac{3}{4}:\dfrac{7}{20}=\dfrac{3}{4}\cdot\dfrac{20}{7}=\dfrac{15}{7}$

d: $\dfrac{10}{11}+\dfrac{4}{11}:4-\dfrac{1}{8}$

$=\dfrac{10}{11}+\dfrac{1}{11}-\dfrac{1}{8}=\dfrac{7}{8}$

Tính:a) $\dfrac{2}{3}\times\dfrac{5}{8}+\dfrac{7}{4}$ b) $\dfrac{8}{5}:\left(\dfrac{4}{3}-\dfrac{5}{6}\right)$ ...

D

datcoder

CTVVIP

2 tháng 11 2023

1

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

Đ, S?a) $\dfrac{1}{2}-\dfrac{1}{8}=\dfrac{3}{8}$ b) $\dfrac{7}{10}-\dfrac{1}{5}=\dfrac{6}{5}$ c) $\dfrac{5}{4}+\dfrac{5}{12}=\dfrac{5}{16}$ ...

ML

Minh Lệ

24 tháng 8 2023

Tính:a) $\dfrac{2}{5}\times\dfrac{3}{8}\times\dfrac{3}{4}$ b) $\dfrac{1}{3}\times\dfrac{1}{6}\times\dfrac{1}{9}$c) $\dfrac{3}{4}:\dfrac{1}{5}:\dfrac{7}{8}$ ...

1

乇尺尺のﾚ

24 tháng 8 2023

a) Đ

b) S

$\dfrac{7}{10}-\dfrac{1}{5} \\ =\dfrac{7}{10}-\dfrac{2}{10}\\ =\dfrac{5}{10}=\dfrac{1}{2}$

c) S

$\dfrac{5}{4}+\dfrac{5}{12}\\ =\dfrac{15}{12}+\dfrac{5}{12}\\ =\dfrac{20}{12}=\dfrac{5}{3}$

d) Đ

Đúng(2)

D

datcoder

CTVVIP

31 tháng 10 2023

1

HQ

Hà Quang Minh

Giáo viên

27 tháng 11 2023

a) $\frac{2}{5} \times \frac{3}{8} \times \frac{3}{4} = \frac{{2 \times 3 \times 3}}{{5 \times 8 \times 4}} = \frac{{18}}{{160}} = \frac{9}{{80}}$

b) $\frac{1}{3} \times \frac{1}{6} \times \frac{1}{9} = \frac{{1 \times 1 \times 1}}{{3 \times 6 \times 9}} = \frac{1}{{162}}$

c) $\frac{3}{4}:\frac{1}{5}:\frac{7}{8} = \frac{3}{4} \times \frac{5}{1} \times \frac{8}{7} = \frac{{3 \times 5 \times 8}}{{4 \times 1 \times 7}} = \frac{{120}}{{28}} = \frac{{30}}{7}$

d) $\frac{3}{5}:\frac{1}{5}:\frac{3}{8} = \frac{3}{5} \times \frac{5}{1} \times \frac{8}{3} = \frac{{3 \times 5 \times 8}}{{5 \times 1 \times 3}} = 8$

Tính:a) $\dfrac{7}{3}+\dfrac{4}{9}$ b) $\dfrac{3}{14}+6$ c) $\dfrac{7}{8}-\dfrac{1}{2}$ ...

D

datcoder

CTVVIP

31 tháng 10 2023