MSC:60 NHA BẠN 

ko bé ơi 

lớp tui có bạn cũng tên Nguyễn Trung Hiếu

giúp mình với

a)\(\dfrac{7}{8}=\dfrac{7}{8};\dfrac{9}{8}=\dfrac{9}{8}\)

b)\(\dfrac{2}{3}=\dfrac{40}{60};\dfrac{3}{4}=\dfrac{45}{60};\dfrac{6}{5}=\dfrac{72}{60}\)

c)\(\dfrac{13}{12}=\dfrac{65}{60};\dfrac{5}{6}=\dfrac{50}{60};\dfrac{4}{5}=\dfrac{48}{60}\)

d)\(\dfrac{9}{8}=\dfrac{54}{48};\dfrac{7}{24}=\dfrac{14}{48};\dfrac{41}{48}=\dfrac{41}{48}\)

xem trong SGK

\(\dfrac{7\times2}{1\times2}=\dfrac{14}{2},\dfrac{9}{2};\dfrac{81\times3}{7\times3}=\dfrac{243}{21},\dfrac{9}{21}\\ \dfrac{4\times2}{3\times2}=\dfrac{8}{6},\dfrac{16}{6};\dfrac{5\times3}{2\times3}=\dfrac{15}{6},\dfrac{19\times2}{3\times2}=\dfrac{38}{6}\)

7/1 và 9/2

Mẫu chung 2

 81/7 và 9/21

Mẫu chung 21

\(\dfrac{7\times2}{1\times2}=\dfrac{14}{2}.và.\dfrac{9}{2};\dfrac{81\times3}{7\times3}=\dfrac{243}{21}và\dfrac{9}{21}\)

Máy mik bị mờ cam thông cảm

\(\dfrac{3}{2}=\dfrac{3\times225}{2\times225}=\dfrac{675}{450}\)

\(\dfrac{7}{9}=\dfrac{7\times50}{9\times50}=\dfrac{350}{450}\)

\(\dfrac{4}{25}=\dfrac{4\times18}{25\times18}=\dfrac{72}{450}\).

\(\dfrac{3}{2}\text{=}\dfrac{3\times225}{2\times225}\text{=}\dfrac{675}{450}\)

\(\dfrac{7}{9}\text{=}\dfrac{7\times50}{9\times50}\text{=}\dfrac{350}{450}\)

\(\dfrac{4}{25}\text{=}\dfrac{4\times18}{25\times18}\text{=}\dfrac{72}{450}\)