a,7/30=28/120;11/60=22/120;9/40=27/120

b,4/7=24/42;5/14=15/42;2/21=4/42 và 9/42

c,17/60=51/180;5/18=50/180;64/90=128/180

a: 7/30=28/120

13/60=26/120

-9/40=-27/120

b: -3/5=-18/30

-5/6=-25/30

3=90/30

c: -4/7=-36/63

8/9=56/63

-10/21=-30/63

d: -3/20=-9/60

-11/-30=11/30=22/60

7/15=28/60

A)\(\frac{3}{5}=\frac{42}{70};\frac{4}{7}=\frac{40}{70};\frac{5}{10}=\frac{35}{70}\)

B)\(\frac{4}{9}=\frac{8}{18};\frac{11}{18}=\frac{11}{18};\frac{5}{6}=\frac{15}{18}\)

Ta có : MSC : 396

\(\frac{3}{44}=\frac{3\cdot9}{44\cdot9}=\frac{27}{396}\)

\(\frac{-11}{18}=\frac{-11\cdot22}{18\cdot22}=\frac{-242}{396}\)

\(\frac{5}{-36}=\frac{-5}{36}=\frac{-5\cdot11}{36\cdot11}=\frac{-55}{396}\)

a, \(\frac{11}{120}=\frac{11.40}{120.40}=\frac{440}{4800}\)

\(\frac{7}{40}=\frac{7.120}{40.120}=\frac{840}{4800}\)

b,\(\frac{24}{146}=\frac{24.13}{146.13}=\frac{312}{1898}\)

\(\frac{6}{13}=\frac{6.146}{13.146}=\frac{876}{1898}\)

c,\(\frac{7}{30}=\frac{7.60.40}{30.60.40}=\frac{16800}{72000}\)

\(\frac{13}{60}=\frac{13.30.40}{60.30.40}=\frac{15600}{72000}\)

\(\frac{-9}{40}=\frac{-9.60.30}{40.60.30}=\frac{-16200}{72000}\)

d,\(\frac{17}{60}=\frac{17.18.90}{60.18.90}=\frac{27540}{97200}\)

\(\frac{-5}{18}=\frac{-5.60.90}{18.60.90}=\frac{-27000}{97200}\)

\(\frac{-64}{90}=\frac{-64.18.60}{90.18.60}=\frac{-69120}{97200}\)

740 =7.12040.120 =8404800 

b,24146 =24.13146.13 =3121898 

1360 =13.30.4060.30.40 =1560072000 

−940 =−9.60.3040.60.30 =−1620072000 

d,1760 =17.18.9060.18.90 =2754097200 

−518 =−5.60.9018.60.90 =−2700097200 

−6490 =−64.18.6090.18.60 =−6912097200 

6

a: \(\dfrac{11}{42}=\dfrac{11\cdot1}{42\cdot1}=\dfrac{11}{42}\)

\(\dfrac{5}{6}=\dfrac{5\cdot7}{6\cdot7}=\dfrac{35}{42}\)

 b: \(\dfrac{40}{7}=\dfrac{40\cdot4}{7\cdot4}=\dfrac{160}{28}\)

\(\dfrac{10}{28}=\dfrac{10\cdot1}{28\cdot1}=\dfrac{10}{28}\)

c: \(\dfrac{4}{15}=\dfrac{4\cdot4}{15\cdot4}=\dfrac{16}{60}\)

\(\dfrac{14}{60}=\dfrac{14\cdot1}{60\cdot1}=\dfrac{14}{60}\)

a)\(\dfrac{11}{42}=\dfrac{35}{42}\)

b) \(\dfrac{160}{28}=\dfrac{10}{28}\)

c) \(\dfrac{16}{60}=\dfrac{14}{60}\)

Bài 1:

a. \(\frac{315}{100}=3\frac{3}{20}\)                         \(\frac{89}{10}=8\frac{9}{10}\)                           \(\frac{124}{50}=2\frac{12}{25}\)                       \(\frac{100}{24}=4\frac{1}{6}\)

b. \(\frac{60}{21}=2\frac{6}{7}\)                              \(\frac{45}{14}=3\frac{3}{14}\)                           \(\frac{123}{11}=11\frac{2}{11}\)                      \(\frac{139}{13}=10\frac{9}{13}\)

1.a,\(\frac{315}{100}\)=\(\frac{300}{100}+\frac{15}{100}=3+\frac{15}{100}=3\frac{15}{100}\)     ;   \(\frac{89}{10}=\frac{80}{10}+\frac{9}{10}=8+\frac{9}{10}=8\frac{9}{10}\)

\(\frac{124}{50}=\frac{100}{50}+\frac{24}{50}=2+\frac{24}{50}=2\frac{24}{50}\)               ;   \(\frac{100}{24}=\frac{96}{24}+\frac{4}{24}=4+\frac{4}{24}=4\frac{4}{24}\)

b, tương tự trên mình làm ngắn hơn nha

\(\frac{60}{21}=2\frac{18}{21}\)     \(\frac{45}{14}=3\frac{3}{14}\)   \(\frac{123}{11}=11\frac{2}{11}\)  \(\frac{139}{13}=10\frac{9}{13}\)