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26 tháng 3 2017

a. \(M=\left(\frac{12}{13}+\frac{21}{65}\right):\frac{81}{13}\)

\(M=\left(\frac{120}{130}+\frac{42}{130}\right).\frac{13}{81}\)

\(M=\frac{81}{65}.\frac{13}{81}\)

\(M=\frac{1}{5}\)

26 tháng 3 2017

M=(12.107/13.107 + 21.10101/65.10101):27.3/13=(12/13 + 21/65):27.3/13

=[(12.5+21)/65]:27.3/13

=81/13.5 : 27.3/13 =81/(5.27.3)=1/5

Đs: M=1/5

\(M=\left(\dfrac{12}{13}+\dfrac{21}{65}\right):\dfrac{9}{13}=\dfrac{81}{65}\cdot\dfrac{13}{9}=\dfrac{1}{5}\cdot9=\dfrac{9}{5}\)

10 tháng 3 2021

Bạn ơi kết quả đúng là \(-\dfrac{5}{6}\)

24 tháng 12 2023

a: \(A=\dfrac{1-\dfrac{1}{\sqrt{49}}+\dfrac{1}{49}-\dfrac{1}{\left(7\sqrt{7}\right)^2}}{\dfrac{\sqrt{64}}{2}-\dfrac{4}{7}+\left(\dfrac{2}{7}\right)^2-\dfrac{4}{343}}\)

\(=\dfrac{1-\dfrac{1}{7}+\dfrac{1}{49}-\dfrac{1}{343}}{4-\dfrac{4}{7}+\dfrac{4}{49}-\dfrac{4}{343}}\)

\(=\dfrac{1-\dfrac{1}{7}+\dfrac{1}{49}-\dfrac{1}{343}}{4\left(1-\dfrac{1}{7}+\dfrac{1}{49}-\dfrac{1}{343}\right)}=\dfrac{1}{4}\)

b: \(M=1-\dfrac{5}{\sqrt{196}}-\dfrac{5}{\left(2\sqrt{21}\right)^2}-\dfrac{\sqrt{25}}{204}-\dfrac{\left(\sqrt{5}\right)^2}{374}\)

\(=1-\dfrac{5}{14}-\dfrac{5}{84}-\dfrac{5}{204}-\dfrac{5}{374}\)

\(=1-5\left(\dfrac{1}{14}+\dfrac{1}{84}+\dfrac{1}{204}+\dfrac{1}{374}\right)\)

\(=1-5\left(\dfrac{1}{2\cdot7}+\dfrac{1}{7\cdot12}+\dfrac{1}{12\cdot17}+\dfrac{1}{17\cdot22}\right)\)

\(=1-\left(\dfrac{5}{2\cdot7}+\dfrac{5}{7\cdot12}+\dfrac{5}{12\cdot17}+\dfrac{5}{17\cdot22}\right)\)

\(=1-\left(\dfrac{1}{2}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{12}+\dfrac{1}{12}-\dfrac{1}{17}+\dfrac{1}{17}-\dfrac{1}{22}\right)\)

\(=1-\left(\dfrac{1}{2}-\dfrac{1}{22}\right)\)

\(=1-\dfrac{11-1}{22}=1-\dfrac{10}{22}=\dfrac{12}{22}=\dfrac{6}{11}\)

a: =3/4-19/18-3/4

=-19/18

b: =24-24x47-24x54

=24(1-47-54)

=24x(-100)=-2400

9 tháng 3 2022

a) \(=\dfrac{-19}{18}\)

b) \(=-2400\)

10 tháng 12 2017

= 18 x ( \(\dfrac{19}{21}\)+\(\dfrac{8}{9}\))+27 x \(\dfrac{17}{27}\)

=18 x \(\dfrac{113}{63}\)+27 x \(\dfrac{17}{27}\)

=\(\dfrac{226}{7}\)+17

=\(\dfrac{345}{7}\)

Chúc bạn học tốt!!

b: =1,6+2,7-4,2-94*0,7+99*2,7

=100*2,7-100*0,7+1,6

=200+1,6

=201,6

a: \(=\dfrac{4832}{16038}=\dfrac{2416}{8019}\)

a: \(=\dfrac{99}{100}:\left(\dfrac{3}{12}-\dfrac{1}{12}+\dfrac{4}{12}\right)-\dfrac{49}{25}\)

\(=\dfrac{99}{100}:\dfrac{1}{2}-\dfrac{49}{25}\)

\(=\dfrac{99}{50}-\dfrac{98}{50}=\dfrac{1}{50}\)

b: \(=\dfrac{13}{15}\cdot\dfrac{1}{4}\cdot3+\left(\dfrac{32}{60}-1-\dfrac{19}{60}\right):\dfrac{47}{24}\)

\(=\dfrac{39}{60}+\dfrac{-19}{60}\cdot\dfrac{24}{47}\)

=459/940