`12/7xx28/21`
`=[3xx4xx4xx7]/[7xx3xx7]`
`=[4xx4]/7=16/7`
\(\dfrac{12}{7}\) x \(\dfrac{28}{21}\) = \(\dfrac{16}{7}\)
\(\dfrac{21}{\cdot}\) x 3 = \(\dfrac{7}{3}\)
a.9 b. 18 c.27 d. 28
bài 2: kết quả phép tính \(\dfrac{7}{19}\) x \(\dfrac{1}{3}\) + \(\dfrac{7}{19}\) x \(\dfrac{2}{3}\)=
a. \(\dfrac{14}{21}\)
b.\(\dfrac{21}{19}\)
c.\(\dfrac{14}{57}\)
d.\(\dfrac{7}{19}\)
\(x:\)\(\dfrac{28}{5}\)\(= \)\(\dfrac{14}{23}\)x\(\dfrac{23}{12}\)
Tính thuận tiện :
M = 3 + \(\dfrac{4}{9}\) x \(\dfrac{7}{25}\) x \(\dfrac{27}{12}\) x \(3\dfrac{4}{7}\) - \(\dfrac{7}{25}\)
Giải giúp e với
A = \(\dfrac{28}{25}\) + \(\dfrac{9}{10}\) - \(\dfrac{11}{15}\) + \(\dfrac{13}{21}\) - \(\dfrac{15}{28}\) + \(\dfrac{17}{26}\) - ... + \(\dfrac{197}{4851}\) - \(\dfrac{199}{4950}\)
\(\dfrac{21}{24}\)x\(\dfrac{2}{11}\):\(\dfrac{9}{8}\)=.......
\(\dfrac{17}{9}\)x\(\dfrac{5}{6}\):\(\dfrac{12}{13}\)=.......
tính giá trị biểu thức :\(\dfrac{3}{4}\) - \(\dfrac{5}{6}\) x ( \(\dfrac{1}{6}\)+ \(\dfrac{1}{8}\)) : \(\dfrac{7}{12}\)
\(\dfrac{15}{14}\) : \(\dfrac{10}{21}\) x \(\dfrac{1}{5}\)
\(5\) x \(\dfrac{1}{5}\) + \(\dfrac{1}{5}\)
\(7\) : \(\dfrac{1}{5}\) - \(\dfrac{1}{5}\)
\(6\) + \(\dfrac{1}{5}\) : \(2\)
\(8\) - \(\dfrac{1}{5}\) x \(7\)
B=\(\dfrac{1}{6}\)+\(\dfrac{1}{15}\)+\(\dfrac{1}{21}\)+\(\dfrac{1}{28}\)+\(\dfrac{1}{36}\)+\(\dfrac{1}{45}\)+\(\dfrac{1}{55}\)+\(\dfrac{1}{66}\)
So sánh hai phân số
a ) \(\dfrac{23}{24}\)và \(\dfrac{24}{23}\) b ) \(\dfrac{4}{21}\)và \(\dfrac{6}{29}\) c ) \(\dfrac{6}{7}\)và \(\dfrac{8}{9}\) d )\(\dfrac{1212}{1313}\)và \(\dfrac{12}{13}\)
giúp mik nha
