Tính giá trị của biểu thức sau:
\(A=\frac{\frac{-4}{5}+\frac{4}{19}-\frac{4}{23}}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}\)
K
Khách
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Những câu hỏi liên quan
23 tháng 7 2016
3) C thiếu đề
4) \(D=\frac{1}{9}-\left|\frac{-5}{23}\right|-\left(\frac{-5}{23}+\frac{1}{9}+\frac{25}{7}\right)+\frac{50}{4}-\frac{7}{30}\)
\(D=\frac{1}{9}-\frac{5}{23}+\frac{5}{23}-\frac{1}{9}-\frac{25}{7}+\frac{50}{4}-\frac{7}{30}\)
\(D=\frac{1}{9}-\frac{1}{9}-\frac{5}{23}+\frac{5}{23}+\frac{-25}{7}+\frac{50}{4}-\frac{7}{30}\)
\(D=0+0+\frac{125}{14}-\frac{7}{30}\)
\(D=\frac{913}{105}\)
HL
8 tháng 8 2021
\(\frac{\frac{-4}{5}+\frac{4}{19}-\frac{4}{23}}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}=\left(-\frac{4}{5}+\frac{4}{19}-\frac{4}{23}\right)\cdot\frac{1}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}=\left(-\frac{4}{5}+\frac{4}{19}-\frac{4}{23}\right)\cdot\frac{1}{-2\cdot\left(-\frac{4}{5}+\frac{4}{19}-\frac{4}{23}\right)}=-\frac{1}{2}\)
27 tháng 3 2018
\(A=\left(4+\frac{1}{5}\right).\frac{19}{8}+\left(2+\frac{5}{8}\right).\frac{21}{5}\) =\(\frac{21}{5}.\frac{19}{8}+\frac{21}{8}.\frac{21}{5}\) =\(\frac{21}{5}.\left(\frac{19}{8}+\frac{21}{8}\right)\) = \(\frac{21}{5}.5\) =21 \(B=\frac{25}{2}.\left(3+\frac{2}{7}\right)-\frac{23}{7}.\left(5+\frac{1}{2}\right)\) =\(\frac{25}{2}.\frac{23}{7}-\frac{23}{7}.\frac{11}{2}\) =\(\frac{23}{7}.\left(\frac{25}{2}-\frac{11}{2}\right)\) =\(\frac{23}{7}.7=23\)
5 tháng 8 2017
Ta có : \(A=\frac{-\frac{4}{9}+\frac{4}{19}-\frac{4}{23}}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}\)
\(\Leftrightarrow A=\frac{-\left(\frac{4}{9}-\frac{4}{19}+\frac{4}{23}\right)}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}\)
\(\Leftrightarrow A=\frac{-4\left(\frac{1}{9}-\frac{1}{19}+\frac{1}{23}\right)}{8\left(\frac{1}{5}-\frac{1}{19}+\frac{1}{23}\right)}\)
\(\Leftrightarrow A=-\frac{4}{8}=-\frac{1}{2}\)
16 tháng 2 2022
\(A=-\frac{\frac{-6}{5}+\frac{6}{19}-\frac{6}{23}}{\frac{9}{5}-\frac{9}{19}+\frac{9}{23}}\)
\(=\frac{-6.\left(\frac{1}{5}-\frac{1}{19}+\frac{1}{23}\right)}{9.\left(\frac{1}{5}-\frac{1}{19}+\frac{1}{23}\right)}\)
\(=-\frac{6}{9}=-\frac{2}{3}\)
NN
0
6 tháng 6 2016
e) \(E=0,7.2\frac{2}{3}.20.0,375.\frac{5}{28}\)
\(=\left(0,7.20\right)\left(2\frac{2}{3}.0,375\right)\frac{5}{28}\)
\(=14.1.\frac{5}{28}\)
\(=14.\frac{5}{28}\)
\(=\frac{5}{2}\)
f) \(F=\left(9,75.21\frac{3}{7}+\frac{39}{4}.18\frac{4}{7}\right)\frac{15}{78}\)
\(=\left(\frac{39}{4}.21\frac{3}{7}+\frac{39}{4}.18\frac{4}{7}\right)\frac{15}{78}\)
\(=\frac{39}{4}\left(21\frac{3}{7}+18\frac{4}{7}\right)\frac{15}{78}\)
\(=\frac{39}{4}.40.\frac{15}{78}\)
\(=390.\frac{15}{78}\)
\(=78\)
Chúc bạn học tốt môn Toán!!!
6 tháng 6 2016
Mình ko ghi đề đâu
\(A=49\frac{8}{23}-5\frac{7}{32}-14\frac{8}{23}=\left(49\frac{8}{23}-14\frac{8}{23}\right)-5\frac{7}{32}=35-5\frac{7}{32}=29\frac{25}{32}\)
\(B=71\frac{38}{45}-43\frac{8}{45}+1\frac{17}{57}=\left(71\frac{38}{45}-43\frac{8}{45}\right)+1\frac{17}{57}=28\frac{2}{3}+1\frac{17}{57}=29\frac{55}{57}\)
\(C=-\frac{3}{7}.\left(\frac{5}{9}+\frac{4}{9}\right)+2\frac{3}{7}=-\frac{3}{7}.1+2\frac{3}{7}=-\frac{3}{7}+2\frac{3}{7}=2\)
\(A=\frac{\frac{-4}{5}+\frac{4}{19}-\frac{4}{23}}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}=\frac{-\left(\frac{4}{5}-\frac{4}{19}+\frac{4}{23}\right)}{2\left(\frac{4}{5}-\frac{4}{19}+\frac{4}{23}\right)}=-\frac{1}{2}\)