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5 tháng 1 2018

\(\frac{28}{23}+\frac{19}{21}-\frac{5}{23}+\frac{7}{10}+\frac{2}{21}\)

\(=\left(\frac{28}{23}-\frac{5}{23}\right)+\left(\frac{19}{21}+\frac{2}{21}\right)+\frac{7}{10}\)

\(=\frac{23}{23}+\frac{21}{21}+\frac{7}{10}\)

\(=1+1+\frac{7}{10}=2\frac{7}{10}=2,7\)

5 tháng 1 2018

28/23+19/21-5/23+7/10+2/21 = 2,7 nhé

6 tháng 12 2018

1, \(\frac{5}{21}+0,5-\frac{19}{23}+\frac{16}{21}-\frac{4}{23}\)

\(=\frac{5+16}{21}-\frac{19+4}{23}+0,5\)

\(=1-1+0,5\)

\(=0,5\)

2,\(\frac{27}{23}+\frac{5}{21}-\frac{4}{23}+\frac{6}{21}+\frac{1}{2}\)

\(=\frac{27-4}{23}+\frac{5+6}{21}+\frac{1}{2}\)

\(=1+\frac{11}{21}+\frac{1}{2}\)

\(=\frac{42+22+21}{42}\)

\(=\frac{85}{42}\)

4 tháng 10 2021

yutyugubhujyikiu

28 tháng 6 2019

a) Ta có:

C = 5/18 + 8/19 - 7/21 + (-10/36 + 11/19 + 1/3) - 5/8

C = 5/18 + 8/19 - 1/3 - 5/18 + 11/19 + 1/3 - 5/8

C = (5/18 - 5/18) + (8/19 + 11/19) - (1/3  - 1/3) - 5/8

C = 1 - 5/8

c = 3/8

b) F = 15/14 - (17/23 - 80/87 + 5/4) + (17/23 - 15/14 + 1/4)

F = 15/14 - 17/23 + 80/87 - 5/4 + 17/23 - 15/14 + 1/4

F = (15/14 - 15/14) - (17/23 - 17/23) + 80/87 - (5/4 - 1/4)

F = 80/87 - 1

F = -7/87

c) G = 1/25 - 4/27 + (-23/27 + -1/25 - 5/43) + 5/43 - 4/7

G = 1/25 - 4/27 - 23/27 - 1/25 - 5/43 + 5/43 - 4/7

G = (1/25 - 1/25) - (4/27 + 23/27) - (5/43 - 5/43) - 4/7

G = -1 - 4/7 = -11/7

\(=\dfrac{5}{21}+\dfrac{16}{21}-\left(\dfrac{19}{23}+\dfrac{4}{23}\right)+\dfrac{1}{2}=\dfrac{1}{2}\)

13 tháng 12 2017

\(\dfrac{5}{21}+0,5-\dfrac{19}{23}+\dfrac{16}{21}-\dfrac{4}{23}\)

\(=\left(\dfrac{5}{21}+\dfrac{16}{21}\right)-\left(\dfrac{19}{23}+\dfrac{4}{23}\right)+0,5\)

\(=1-1+0,5\)

\(=0,5\)

13 tháng 12 2017

\(\dfrac{5}{21}+0,5-\dfrac{19}{23}+\dfrac{16}{21}-\dfrac{4}{23}\)

=\(\dfrac{5}{21}+\dfrac{1}{2}-\dfrac{19}{23}+\dfrac{16}{21}-\dfrac{4}{23}\)

=\(\left(\dfrac{5}{21}+\dfrac{16}{21}\right)+\left(\dfrac{-19}{23}+\dfrac{-4}{23}\right)+\dfrac{1}{2}\)

= 1 + (-1) +\(\dfrac{1}{2}\) = 0 + \(\dfrac{1}{2}\) =\(\dfrac{1}{2}\)

a) \(1\frac{4}{23}+\frac{5}{21}-\frac{4}{23}+0,5+\frac{16}{21}\)

\(=1\frac{4}{23}-\frac{4}{23}+\left(\frac{5}{21}+\frac{16}{21}\right)+0,5\)

\(=1+1+0,5=2,5\)

b) \(\frac{3}{7}.19\frac{1}{3}-\frac{3}{7}.33\frac{1}{3}=\frac{3}{7}.\left(19\frac{1}{3}-33\frac{1}{3}\right)\)

\(=\frac{3}{7}.\left(-14\right)=-6\)

c) \(15\frac{1}{4}:\left(-\frac{5}{7}\right)-25\frac{1}{4}:\left(-\frac{5}{7}\right)\)

\(=\left(15\frac{1}{4}-25\frac{1}{4}\right):\left(-\frac{5}{7}\right)\)

\(=\left(-10\right):\left(-\frac{5}{7}\right)\)

\(=14\)

7 tháng 8 2019

a) \(1\frac{4}{23}+\frac{5}{21}-\frac{4}{23}+0,5+\frac{16}{21}\)

\(=\left(\frac{27}{23}-\frac{4}{23}\right)+\left(\frac{5}{21}+\frac{16}{21}\right)+0,5\)

\(=1+1+0,5\)

\(=2+0,5\)

\(=2,5.\)

b) \(\frac{3}{7}.19\frac{1}{3}-\frac{3}{7}.33\frac{1}{3}\)

\(=\frac{3}{7}.\left(\frac{58}{3}-\frac{100}{3}\right)\)

\(=\frac{3}{7}.\left(-14\right)\)

\(=-6.\)

c) \(15\frac{1}{4}:\left(-\frac{5}{7}\right)-25\frac{1}{4}:\left(-\frac{5}{7}\right)\)

\(=\left(\frac{61}{4}-\frac{101}{4}\right):\left(-\frac{5}{7}\right)\)

\(=\left(-10\right):\left(-\frac{5}{7}\right)\)

\(=14.\)

Chúc bạn học tốt!

25 tháng 12 2017

Tính 1 câu thoy nhé !

\(\dfrac{3}{7}.19\dfrac{1}{3}-\dfrac{3}{7}.33\dfrac{1}{3}\)

= \(\dfrac{3}{7}.\left(19\dfrac{1}{3}-33\dfrac{1}{3}\right)\)

=\(\dfrac{3}{7}.-14=-6\)

14 tháng 12 2019

\(\frac{5}{21}\)+ \(0,5\) - \(\frac{19}{23}+\frac{16}{21}-\frac{4}{23}\)= 0,5

Chúc học tốt!!!

14 tháng 12 2019

bạn ghi rõ được ko