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4 và 2/5 + 5 và 6/9 +2 và 3/4 + 3/5+1/3+1/4
= 22/5+51/9+11/4+3/5+1/3+1/4
=(22/5+3/5)+(51/9+1/3)+(11/4+1/4)
=25/5+54/9+12/4
=5+6+3
=14
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\(C=\dfrac{3}{7}\times\dfrac{5}{9}+\dfrac{4}{9}\times\dfrac{3}{7}-\dfrac{3}{7}\)
\(=\dfrac{3}{7}\times\dfrac{5}{9}+\dfrac{4}{9}\times\dfrac{3}{7}-\dfrac{3}{7}\times1\)
\(=\dfrac{3}{7}\times\left(\dfrac{5}{9}+\dfrac{4}{9}-1\right)\)
\(=\dfrac{3}{7}\times0=0\)
\(D=8\dfrac{2}{7}-\left(3\dfrac{4}{9}+4\dfrac{2}{7}\right)\)
\(=\dfrac{58}{7}-\left(\dfrac{31}{9}+\dfrac{30}{7}\right)\)
\(=\dfrac{58}{7}-\dfrac{31}{9}-\dfrac{30}{7}\)
\(=\left(\dfrac{58}{7}-\dfrac{30}{7}\right)-\dfrac{31}{9}\)
\(=4-\dfrac{31}{9}=\dfrac{36}{9}-\dfrac{31}{9}\)
\(=\dfrac{5}{9}\)
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Tk mình đi mọi người mình bị âm nè!
ai tk mình mình tk lại cho!!!
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` a) 4 8/23 + 5 7/8 - 9 8/23 `
`= 100/23 + 47/8 - 215/23 `
`= ( 100/23 - 215/23) + 47/8 `
`= -115/23 + 47/8 `
`= -5 + 47/8 `
`= -5/1 + 47/8 `
`= -40/8 + 47/8 `
`=7/8`
`b) 8 2/7 - ( 3 4/9 + 4 2/7 ) `
`= 58/7 - 31/9 - 30/7 `
`= (58/7 - 30/7 ) - 31/9 `
`= 28/7 - 31/9 `
` = 252/63 - 217/63 `
`= 35/63`
`= 5/9`
`@ animephamdanhv.`
a)\(4\dfrac{8}{23}+5\dfrac{7}{8}-9\dfrac{8}{23}=\dfrac{100}{23}+\dfrac{47}{8}-\dfrac{215}{23}=\dfrac{100}{23}-\dfrac{215}{23}+\dfrac{47}{8}=-\dfrac{115}{23}+\dfrac{47}{8}=-5+\dfrac{47}{8}=\dfrac{7}{8}\)
b) \(8\dfrac{2}{7}-\left(3\dfrac{4}{9}+4\dfrac{2}{7}\right)=\dfrac{58}{7}-\left(\dfrac{31}{9}+\dfrac{30}{7}\right)=\dfrac{58}{7}-\dfrac{31}{9}-\dfrac{30}{7}=\dfrac{58}{7}-\dfrac{30}{7}-\dfrac{31}{9}=4-\dfrac{31}{9}=\dfrac{5}{9}\)