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23 tháng 6 2018

a.3/7*49/6+3/4*-12/33

   =7/2-3/11

=71/22

b.5/3*14/9+1/6-2/10

=-70/27-1/30

=-709/270

9 tháng 3 2018

các bn lm đến đâu cx dc miễn là lm hộ mk cái ạ, ai đang lm vào nhắn tin vs mk để mk bít nha

19 tháng 2 2024

a; \(-\dfrac{8}{3}+\dfrac{7}{5}-\dfrac{71}{15}< x< -\dfrac{13}{7}+\dfrac{19}{14}-\dfrac{7}{2}\)

              -\(\dfrac{19}{15}\) - \(\dfrac{71}{15}\) < \(x\) < -\(\dfrac{1}{2}\) - \(\dfrac{7}{2}\)

              -6 < \(x\) < -4

             vì \(x\) \(\in\) Z nên \(x\) = -5

14 tháng 8 2020

a)2/3 + 5+3/7:2+4/49.(-7)+1/2.(-2)\(^4\)

= 2/3+5+3/14+-4/7+8

=(2/3+3/14+-4/7)+(5+8)

=13/42+13

=559/42

b)2+3/4.(-0,4)-1-3/5.2,75+(-1/2):4/11

=2+(-0,3) - 1 - 1,65 + (-11/8)

= -2,325

c)( 2 + 1/3 +3 +1/2 ) : ( -4 - 1/6 +3 +1/7 ) +7 +1/2

=35/6 : -43/42 + 7 + 1/2

= -245/43 +7 +1/2

= 155/86

d) 2/3+ -5/12

= 8/12 + -5/12

= 3/12 

e) -2/3 . -9/12 

\(\frac{-2.-9}{3.12}\)

= 18/36

=1/2

14 tháng 8 2020

f) -2/9 - 7/12

=\(\frac{-24}{108}\)-  \(\frac{14}{108}\)

\(\frac{-38}{108}\)

=\(\frac{-19}{54}\)

g) 2/3 : -4/9

\(\frac{2}{3}\)\(\frac{-9}{4}\)

= -3/2

h) 4 . ( -1/3)\(^3\)- 2 . ( -1/2)\(^2\)+3 .( 1/2 ) +1

=- 4 . 1/27 - 2 . 1/4 + 3 .1/2 +1 

= -4/27 - 1/2 + 3/2 + 1

= 50 / 27

k ) ( 4 - 5/12 ) : 2 +5/24

= 43/12 : 2 +5/24

= 43/24 + 5/24

= 48/24

= 2

26 tháng 6 2020

\(a)\)\(6\frac{4}{5}-\left(1\frac{2}{3}+3\frac{4}{5}\right)\)

\(=6\frac{4}{5}-1\frac{2}{3}-3\frac{4}{5}\)

\(=\left(6\frac{4}{5}-3\frac{4}{5}\right)-1\frac{2}{3}\)

\(=\left(6+\frac{4}{5}-3-\frac{4}{5}\right)-\frac{5}{3}\)

\(=3-\frac{5}{3}\)

\(=\frac{9}{3}-\frac{5}{3}\)

\(=\frac{4}{3}\)

\(b)\)\(6\frac{5}{7}-(1\frac{3}{4}+2\frac{5}{7})\)

\(=6\frac{5}{7}-1\frac{3}{4}-2\frac{5}{7}\)

\(=\left(6\frac{5}{7}-2\frac{5}{7}\right)-1\frac{3}{4}\)

\(=\left(6+\frac{5}{7}-2-\frac{5}{7}\right)-\frac{7}{4}\)

\(=4-\frac{7}{4}\)

\(=\frac{16}{4}-\frac{7}{4}\)

\(=\frac{9}{4}\)

\(c)\)\(7\frac{5}{9}-\left(2\frac{3}{4}+3\frac{5}{9}\right)\)

\(=7\frac{5}{9}-2\frac{3}{4}-3\frac{5}{9}\)

\(=\left(7\frac{5}{9}-3\frac{5}{9}\right)-2\frac{3}{4}\)

\(=\left(7+\frac{5}{9}-3-\frac{5}{9}\right)-\frac{11}{4}\)

\(=4-\frac{11}{4}\)

\(=\frac{16}{4}-\frac{11}{4}\)

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

P/s: Câu b bạn thiếu ngoặc.

Linz

26 tháng 6 2020

 a) 6 và 4/5 - ( 1 và 2/3 + 3 và 4/5)

= 34/5- ( 5/3 + 19/5 )

= 34/5 - 5/3 - 19/5

= (34/5 - 9/5 ) - 5/3

=25/5 -5/3

= 5/1 - 5/3

= 15/3 - 5/3

=10/3

b) 6 và 5/7 - (1 và 3/4 + 2 và 5/7)

=47/7 - (7/4 + 19/7 )

= 47/7 -7/4 - 19/7

= (47/7 -19/7 ) - 7/4

= 28/7 -7/4

=4/1 - 7/4

= 16/4 - 7/4

= 9/4

c) 7 và 5/9 - ( 2 và 3/4 + 3 và 5/9 )

= 68/9 - ( 11/4 + 32/9 )

= 68/9 - 11/4 - 32/9

= (68/9 - 32/9 )- 11/4

= 36/9 -11/4

= 4/1 - 11/4

= 16/4 - 11/4

= 5/4

    Chúc bạn học tốt nha!!!!!

3 tháng 7 2018

\(-\frac{1}{10}< =x< =\frac{3}{5}\) 

\(\frac{-4}{9}< x< =\frac{2}{3}\)

3 tháng 7 2018

Đoàn Thị Thanh Ngân viết lời giải hộ thanks

a: \(=\dfrac{-1}{4}+\dfrac{7}{33}-\dfrac{5}{3}-\dfrac{5}{4}-\dfrac{6}{11}+\dfrac{48}{49}\)

\(=\dfrac{-3}{2}+\dfrac{7}{33}-\dfrac{18}{33}-\dfrac{5}{3}+\dfrac{48}{49}\)

\(=\dfrac{-9-10}{6}+\dfrac{-11}{33}+\dfrac{48}{49}\)

\(=\dfrac{-19}{6}+\dfrac{-1}{3}+\dfrac{48}{49}=-\dfrac{247}{98}\)

b: \(=\dfrac{11}{125}-\dfrac{17}{18}+\dfrac{4}{9}-\dfrac{5}{7}+\dfrac{17}{14}\)

\(=\dfrac{11}{125}+\dfrac{-17+8}{9}+\dfrac{-10+17}{14}\)

\(=\dfrac{11}{125}-1+\dfrac{7}{14}=\dfrac{11}{125}+\dfrac{1}{2}=\dfrac{22+125}{250}=\dfrac{147}{250}\)

 

14 tháng 3 2020

a,

A=1−3−5−7−9−...−97−99a)A=1−3−5−7−9−...−97−99 

=1−(3+5+7+...+99)=1−(3+5+7+...+99)

=1−(99+3).[(99−3):2+1]2=1−(99+3).[(99−3):2+1]2
=1−2499=−2498=1−2499=−2498

b)B=1+3−5−7+9+...+97−99b)B=1+3−5−7+9+...+97−99
=(−8)+(−8)+(−8)+...+(−8)+97−99=(−8)+(−8)+(−8)+...+(−8)+97−99
=(−8).12+(−2)=−98=(−8).12+(−2)=−98

c)C=1−3−5+7+9−11−13+15+...+97−99c)C=1−3−5+7+9−11−13+15+...+97−99
=0+0+0+0+0+...+0−99=0+0+0+0+0+...+0−99
=−99

19 tháng 7 2017

a= -1/7

b -50/21

c   1/8

d 19/56

e-13/24

f -89/312

11 tháng 6 2024

a; \(\dfrac{3}{11}\) + \(\dfrac{5}{-9}\) + \(\dfrac{4}{11}\) - \(\dfrac{4}{9}\) + \(\dfrac{3}{17}\) + \(\dfrac{15}{11}\)

= (\(\dfrac{3}{11}\) + \(\dfrac{4}{11}\) + \(\dfrac{15}{11}\)) - (\(\dfrac{5}{9}\) + \(\dfrac{4}{9}\)) + \(\dfrac{3}{17}\)

= 2 - 1 + \(\dfrac{3}{17}\)

= 1 + \(\dfrac{3}{17}\)

\(\dfrac{20}{17}\) 

11 tháng 6 2024

c; N = \(\dfrac{\dfrac{5}{7}-\dfrac{5}{9}-\dfrac{5}{11}}{\dfrac{15}{7}+\dfrac{15}{9}+\dfrac{15}{11}}\)

   Phải là - \(\dfrac{5}{7}\) chỗ tử số mới đúng em nhé!

2 tháng 4 2017

Bài 1: Tính

\(\text{1)}\) \(\dfrac{5}{8}.\dfrac{7}{30}-\dfrac{5}{2}.\dfrac{1}{8}\)

\(=\dfrac{5}{8}.\dfrac{7}{30}-\dfrac{5}{8}.\dfrac{1}{2}\)

\(=\dfrac{5}{8}.\left(\dfrac{7}{30}-\dfrac{1}{2}\right)\)

\(=\dfrac{5}{8}.\dfrac{-4}{15}\)

\(=\dfrac{-1}{6}\)

\(\text{2)}\) \(\dfrac{21}{10}.\dfrac{3}{4}-\dfrac{21}{10}-\dfrac{3}{4}\)

\(=\dfrac{63}{40}-\dfrac{21}{10}-\dfrac{3}{4}\)

\(=\dfrac{-21}{40}-\dfrac{3}{4}\)

\(=\dfrac{-51}{40}\)

\(\text{3)}\) \(\dfrac{-4}{11}:\dfrac{-6}{11}\)

\(=\dfrac{-4}{11}.\dfrac{11}{-6}\)

\(=\dfrac{4}{6}\)

\(\text{4)}\) \(\dfrac{2}{7}.\dfrac{14}{3}-1\)

\(=\dfrac{4}{3}-1\)

\(=\dfrac{1}{3}\)

\(\text{5)}\) \(\dfrac{4}{7}:\left(\dfrac{1}{5}.\dfrac{4}{7}\right)\)

\(=\dfrac{4}{7}:\dfrac{1}{5}:\dfrac{4}{7}\)

\(=1:\dfrac{1}{5}\)

\(=5\)

\(\text{6)}\) \(\dfrac{12}{7}.\dfrac{7}{4}+\dfrac{35}{11}:\dfrac{245}{121}\)

\(=3+\dfrac{35}{11}.\dfrac{121}{245}\)

\(=3+\dfrac{11}{7}\)

\(=3\dfrac{11}{7}=\dfrac{32}{7}\)

\(\text{7)}\) \(\left(\dfrac{4}{3}+\dfrac{8}{3}\right).\left(\dfrac{7}{4}-\dfrac{6}{4}\right):\left(\dfrac{6}{5}+\dfrac{12}{5}+\dfrac{1}{5}\right)\)

\(=4.\left(\dfrac{7}{4}-\dfrac{6}{4}\right):\left(\dfrac{6}{5}+\dfrac{12}{5}+\dfrac{1}{5}\right)\)

\(=4.\dfrac{1}{4}:\left(\dfrac{6}{5}+\dfrac{12}{5}+\dfrac{1}{5}\right)\)

\(=4.\dfrac{1}{4}:\dfrac{19}{5}\)

\(=1:\dfrac{19}{5}\)

\(=\dfrac{5}{19}\)

\(\text{8)}\) \(\left(\dfrac{1}{4}-\dfrac{1}{4}+\dfrac{\dfrac{1}{9}}{\dfrac{1}{9}}\right):\left(\dfrac{2}{3}+\dfrac{\dfrac{7}{15}}{\dfrac{2}{5}}-\dfrac{1}{6}\right)\)

\(=\left(0+1\right):\left(\dfrac{2}{3}+\dfrac{7}{15}:\dfrac{2}{5}-\dfrac{1}{6}\right)\)

\(=1:\left(\dfrac{2}{3}+\dfrac{7}{6}-\dfrac{1}{6}\right)\)

\(=1:\left(\dfrac{2}{3}+1\right)\)

\(=1:\dfrac{5}{3}\)

\(=\dfrac{3}{5}\)
\(\text{9)}\)

\(\left[\left(\dfrac{2}{193}-\dfrac{3}{389}\right).\dfrac{193}{17}+\dfrac{33}{34}\right]:\left[\left(\dfrac{7}{1931}-\dfrac{11}{3862}\right).\dfrac{1931}{25}+\dfrac{9}{2}\right]\)

\(=\left[\dfrac{199}{75077}.\dfrac{193}{17}+\dfrac{33}{34}\right]:\left[\left(\dfrac{7}{1931}-\dfrac{11}{3862}\right).\dfrac{1931}{25}+\dfrac{9}{2}\right]\)

\(=\left[\dfrac{199}{6613}+\dfrac{33}{34}\right]:\left[\left(\dfrac{7}{1931}-\dfrac{11}{3862}\right).\dfrac{1931}{25}+\dfrac{9}{2}\right]\)

\(=\dfrac{13235}{13226}:\left[\left(\dfrac{7}{1931}-\dfrac{11}{3862}\right).\dfrac{1931}{25}+\dfrac{9}{2}\right]\)

\(=\dfrac{13235}{13226}:\left[\dfrac{3}{3862}.\dfrac{1931}{25}+\dfrac{9}{2}\right]\)

\(=\dfrac{13235}{13226}:\left[\dfrac{3}{50}+\dfrac{9}{2}\right]\)

\(=\dfrac{13235}{13226}:\dfrac{114}{25}\)

\(=\dfrac{330875}{1507764}\)