a)36/48>12/48

=>6/8>3/12

b)135/225<180/225

=>15/25<36/45

c)1575/2835>1323/2835

=>15/27>49/105

Chúc e học tốt

a) mẫu số chung: 4

\(\dfrac{6}{8}=\dfrac{6:2}{8:2}=\dfrac{3}{4};\dfrac{3}{12}=\dfrac{3:3}{12:3}=\dfrac{1}{4}\)

vì \(\dfrac{3}{4}>\dfrac{1}{4}\)nên \(\dfrac{6}{8}>\dfrac{3}{12}\)

b) mẫu số chung: 5

\(\dfrac{15}{25}=\dfrac{15:5}{25:5}=\dfrac{3}{5};\dfrac{36}{45}=\dfrac{36:9}{45:9}=\dfrac{4}{5}\)

vì\(\dfrac{3}{5}< \dfrac{4}{5}\)nên \(\dfrac{15}{25}< \dfrac{36}{45}\)

a) \(\dfrac{23}{24}< 1\)

\(\dfrac{24}{23}>1\)

\(\Rightarrow\dfrac{23}{24}< \dfrac{24}{23}\)

b) \(\dfrac{4}{21}< \dfrac{4}{20}=\dfrac{1}{5}=\dfrac{6}{30}< \dfrac{6}{29}\)

c) \(\dfrac{6}{7}=1-\dfrac{1}{7}< \dfrac{8}{9}=1-\dfrac{1}{9}\)

d) \(\dfrac{1212}{1313}=\dfrac{12\times101}{13\times101}=\dfrac{12}{13}\)

a)

`6/9=2/3`

`6/24=1/4`

`48/96=1/2`

`42/98=3/7`

b)

`24/36=2/3`

`18/30=3/5`

`15/120=1/8`

`80/240=1/3`

a)\(\dfrac{6}{9}=\dfrac{6:3}{9:3}=\dfrac{2}{3}\)
\(\dfrac{6}{24}=\dfrac{6:6}{24:6}=\dfrac{1}{4}\)
\(\dfrac{48}{96}=\dfrac{48:48}{96:48}=\dfrac{1}{2}\)
\(\dfrac{42}{98}=\dfrac{42:14}{98:14}=\dfrac{3}{7}\)
b)\(\dfrac{24}{36}=\dfrac{24:12}{36:12}=\dfrac{2}{3}\)
\(\dfrac{18}{30}=\dfrac{18:6}{30:6}=\dfrac{3}{5}\)
\(\dfrac{15}{120}=\dfrac{15:15}{120:15}=\dfrac{1}{8}\)
\(\dfrac{80}{240}=\dfrac{80:80}{240:80}=\dfrac{1}{3}\)

\(a,\dfrac{6}{9}=\dfrac{2}{3};\dfrac{6}{24}=\dfrac{1}{4};\dfrac{48}{96}=\dfrac{1}{2};\dfrac{42}{98}=\dfrac{3}{7}\\ b,\dfrac{24}{36}=\dfrac{2}{3};\dfrac{18}{30}=\dfrac{3}{5};\dfrac{15}{120}=\dfrac{1}{8};\dfrac{80}{240}=\dfrac{1}{3}\)

Câu 3:

a) \(\dfrac{12}{36}=\dfrac{12:12}{36:12}=\dfrac{1}{3}\)

\(\dfrac{-16}{20}=\dfrac{-16:4}{20:4}=\dfrac{-4}{5}\)

b) \(\dfrac{21}{105}=\dfrac{21:21}{105:21}=\dfrac{1}{5}\)

\(\dfrac{35}{150}=\dfrac{35:5}{150:5}=\dfrac{7}{30}\)

Câu 4: 

a) \(\dfrac{3}{10}+\dfrac{5}{10}=\dfrac{3+5}{10}=\dfrac{8}{10}=\dfrac{4}{5}\)

b) Ta có: \(\left(-27\right)\cdot36+64\cdot\left(-27\right)+23\cdot\left(-100\right)\)

\(=\left(-27\right)\cdot\left(64+36\right)+23\cdot\left(-100\right)\)

\(=-27\cdot100-23\cdot100\)

\(=100\left(-27-23\right)\)

\(=-50\cdot100=-5000\)

c) \(\dfrac{5}{8}+\dfrac{3}{12}=\dfrac{15}{24}+\dfrac{6}{24}=\dfrac{21}{24}=\dfrac{7}{8}\)

d) Ta có: \(\dfrac{-2}{17}+\dfrac{3}{19}+\dfrac{-15}{17}+\dfrac{16}{19}+\dfrac{5}{6}\)

\(=\left(-\dfrac{2}{17}+\dfrac{-15}{17}\right)+\left(\dfrac{3}{19}+\dfrac{16}{19}\right)+\dfrac{5}{6}\)

\(=-1+1+\dfrac{5}{6}\)

\(=\dfrac{5}{6}\)

a) -23/49 = -1081/2303

   -25/47 = -1225/2303

=> -1081/2303 > -1225/2303 hay -23/49 > -25/47

b) -317/633 = -235531/470319

   -371/743 = -234843/470319

=> -235531/470319 < -234843/470319 hay -317/633 < -371/743

5/7<3/4

8/9>5/6

a) \(\dfrac{5}{7}< \dfrac{3}{4}\)

b) \(\dfrac{8}{9}>\dfrac{5}{6}\)

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43𝑥1⋅92⋅𝑥4𝑥163⋅𝑥5⋅254⋅𝑥6

12𝑥12⋅𝑥4𝑥163⋅𝑥5⋅254⋅𝑥6 

chúc bạn học tốt

4/3x1x9/2x4x16/3x5x25/4x6=172800/144=1200/1

tk nha

1. Từ bé đến lớn: \(\frac{3}{10};\frac{8}{15};\frac{9}{6};\frac{13}{5};\frac{16}{3}\)

2. 

a, Ta có: \(\frac{24}{36}=\frac{6}{9}\)  ;  \(\frac{15}{27}=\frac{5}{9}\)

Vì \(\frac{6}{9}>\frac{5}{9}\)nên \(\frac{24}{36}>\frac{15}{27}\)

P/s: Các câu còn lại tương tự :>