Tính nhanh:
5/23 : ( 3/26 + 7/9) - 5/23 : (23/26 + 2/9)
Ai giải giúp bài này với !
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Những câu hỏi liên quan
NT
0
31 tháng 3 2021
a) Ta có: \(\dfrac{21}{25}\cdot\dfrac{11}{9}\cdot\dfrac{5}{7}\)
\(=\dfrac{21\cdot11\cdot5}{25\cdot9\cdot7}\)
\(=\dfrac{3\cdot7\cdot11\cdot5}{5\cdot5\cdot3\cdot3\cdot7}\)
\(=\dfrac{11}{5\cdot3}=\dfrac{11}{15}\)
NB
2
LT
Lương Thị Vân Anh
CTVHS
22 tháng 3 2023
\(\dfrac{-5}{23}\cdot\dfrac{17}{26}+\dfrac{5}{23}\cdot\dfrac{9}{-29}\)
= \(\dfrac{5}{23}\cdot\dfrac{-17}{26}+\dfrac{5}{23}\cdot\dfrac{-9}{29}\)
= \(\dfrac{5}{23}\left(\dfrac{-17}{26}+\dfrac{-9}{26}\right)\)
= \(\dfrac{5}{23}\cdot\left(-1\right)=\dfrac{-5}{23}\)
NV
Nguyễn Việt Lâm
Giáo viên
22 tháng 3 2023
\(\dfrac{-5}{23}.\dfrac{17}{26}+\dfrac{5}{23}.\dfrac{9}{-26}=\dfrac{-5}{23}.\left(\dfrac{17}{26}+\dfrac{9}{26}\right)\)
\(=\dfrac{-5}{23}.\left(\dfrac{17+9}{26}\right)=\dfrac{-5}{23}.\dfrac{26}{26}\)
\(=\dfrac{-5}{23}.1=\dfrac{-5}{23}\)
KN
13 tháng 4 2023
a) \(\dfrac{-3}{20}\) + \(\dfrac{-7}{4}\) =\(\dfrac{-3}{20}\) + \(\dfrac{-35}{20}\) = -2
b) 6 và \(\dfrac{2}{3}\) - 4 và \(\dfrac{2}{3}\) = 2
c) \(\dfrac{-3}{10}\) + \(\dfrac{7}{12}\) = \(\dfrac{-18}{60}\) + \(\dfrac{35}{60}\) =\(\dfrac{17}{60}\)
d) \(\dfrac{35}{-9}\) . \(\dfrac{81}{7}\) = \(\dfrac{-35}{9}\) . \(\dfrac{81}{7}\) = 45
e) \(\dfrac{-2}{5}\) - \(\dfrac{-3}{4}\) = \(\dfrac{-8}{20}\) - \(\dfrac{-15}{20}\) = \(\dfrac{-8}{20}\) + \(\dfrac{15}{20}\) =\(\dfrac{7}{20}\)
f) \(\dfrac{5}{23}\) . \(\dfrac{7}{26}\) + \(\dfrac{5}{23}\) .\(\dfrac{9}{26}\) = \(\dfrac{5}{23}\) . ( \(\dfrac{7}{26}\) + \(\dfrac{9}{26}\) )= \(\dfrac{5}{23}\) . \(\dfrac{8}{13}\) = \(\dfrac{40}{299}\)
g) \(\dfrac{-3}{12}\) : \(\dfrac{4}{15}\) =\(\dfrac{-3}{12}\) . \(\dfrac{15}{4}\) =\(\dfrac{-5}{8}\)
h) 1 và \(\dfrac{1}{6}\) - 3 và \(\dfrac{1}{3}\) =\(\dfrac{7}{6}\) -\(\dfrac{10}{3}\) = \(\dfrac{-13}{6}\)
i) \(\dfrac{-2}{5}\) . (-3) + \(\dfrac{3}{8}\) . \(\dfrac{4}{-10}\) =(\(\dfrac{-2}{5}\) .\(\dfrac{-4}{10}\)) + [(-3) . \(\dfrac{3}{8}\)
= \(\dfrac{4}{25}\) + \(\dfrac{-9}{8}\) = \(\dfrac{32}{200}\) + \(\dfrac{-225}{200}\) = \(\dfrac{-193}{200}\)
j) \(\dfrac{-13}{17}\) + (\(\dfrac{13}{-21}\) + \(\dfrac{-4}{17}\) )
= ( \(\dfrac{-13}{17}\) + \(\dfrac{-4}{17}\) )+\(\dfrac{-13}{21}\)
= -1+\(\dfrac{-13}{21}\)
= \(\dfrac{-21}{21}\) + \(\dfrac{-13}{21}\) = \(\dfrac{-34}{21}\)
Khôi nguyễn
NT
Nguyễn Thị Thương Hoài
Giáo viên
VIP
19 tháng 8 2023
Bài 2:
a, \(\dfrac{5}{23}\) \(\times\) \(\dfrac{17}{26}\) + \(\dfrac{5}{23}\) \(\times\) \(\dfrac{9}{26}\)
= \(\dfrac{5}{23}\) \(\times\) ( \(\dfrac{17}{26}\) + \(\dfrac{9}{26}\))
= \(\dfrac{5}{23}\) \(\times\) \(\dfrac{26}{26}\)
= \(\dfrac{5}{23}\)
b, \(\dfrac{3}{4}\) \(\times\) \(\dfrac{7}{9}\) + \(\dfrac{7}{4}\) \(\times\) \(\dfrac{3}{9}\)
= \(\dfrac{7}{12}\) + \(\dfrac{7}{12}\)
= \(\dfrac{14}{12}\)
= \(\dfrac{7}{6}\)
5/23 : ( 3/26 + 7/9) - 5/23 : (23/26 + 2/9)
=\(\frac{5}{23}\)\(\div[(\frac{3}{26}+\frac{7}{9})-(\frac{23}{26}+\frac{2}{9})]\)
=\(\frac{5}{23}\div\)\([(\frac{3}{26}+\frac{23}{26})-(\frac{7}{9}+\frac{2}{9})]\)
=\(\frac{5}{23}\div[1-1]\)
=\(\frac{5}{23}\div0\)
=0
5/23 : ( 3/26 + 7/9 ) - 5/23 : ( 23/26 + 2/9 )
=5/23 : { (23/26 + 3/26) - ( 7/9 + 2/9 )
=5/23 : { 1-1 }
=5/23 : 0
=0