\(\dfrac{25}{36}\)

63 / 175 = 9 / 25

47 / 235 = 1 / 5

63 / 72 = 7 / 8

63/175= 9/25; 47/235= 1/5; 63/72=7/8

\(\frac{63}{175}=\frac{7\cdot9}{7\cdot25}=\frac{9}{25}\)

\(\frac{47}{235}=\frac{47}{5\cdot47}=\frac{1}{5}\)

\(\frac{63}{72}=\frac{7\cdot9}{8\cdot9}=\frac{7}{8}\)

\(a)\) \(\dfrac{1}{2}\)\(,\) \(\dfrac{1}{8},\) \(\dfrac{1}{7}.\)

b,(phân số \(\dfrac{7}{8}\) là 1 phân số tối giản)

\(\dfrac{3}{4}\) ; \(\dfrac{1}{7}\)

Phân số tối giản: \(\dfrac{7}{8}\) vì cả tử và mẫu không cùng chia hết cho số tự nhiên nào lớn hơn 1

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)

`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)\(\dfrac{24}{36}=\dfrac{24:12}{36:12}=\dfrac{2}{3}\)
\(\dfrac{18}{30}=\dfrac{18:6}{30:6}=\dfrac{3}{5}\)
\(\dfrac{15}{120}=\dfrac{15:15}{120:15}=\dfrac{1}{8}\)
\(\dfrac{80}{240}=\dfrac{80:80}{240:80}=\dfrac{1}{3}\)

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

1) Các phân số tối giản là: \(\frac{1}{5};\frac{5}{7};\frac{-2}{9}\)

2) a) \(\frac{28}{36}=\frac{28:4}{36:4}=\frac{7}{9}\)

    b) \(\frac{-63}{90}=\frac{-63:9}{90:9}=\frac{-7}{10}\)

   c)  \(\frac{40}{-120}=\frac{40:40}{-120:40}=\frac{-1}{3}\)

3) a) \(\frac{2.4}{6.18}=\frac{2.2.2}{2.3.3.2.3}=\frac{2}{27}\)

   b)  \(\frac{3.5.7}{6.9.14}=\frac{3.5.7}{2.3.9.2.7}=\frac{5}{36}\) 

    c) \(\frac{4.7-4.5}{64}=\frac{4.\left(7-5\right)}{64}=\frac{4.2}{64}=\frac{8}{64}=\frac{1}{8}\)

4) Muốn rút gọn một phân số chưa tối giản, ta tìm ƯCLN của cả hai số ở tử và mẫu, rồi cùng đem cả tử và mẫu chia cho số chung vừa tìm được.

\(\dfrac{-63}{72}=\dfrac{-7}{8}\)

\(\dfrac{20}{-140}=\dfrac{-1}{7}\)

\(\dfrac{3.10}{5.24}=\dfrac{30}{120}=\dfrac{1}{4}\)

\(\dfrac{3.7.11}{22.9}=\dfrac{231}{198}=\dfrac{7}{6}\)

\(\dfrac{8.5-8.2}{16}=\dfrac{24}{16}=\dfrac{3}{2}\)

\(\dfrac{11.4-11}{2-13}=\dfrac{33}{-11}=-3\)

\(\frac{27}{36}\)=\(\frac{3}{4}\)

\(\frac{42}{63}\)=\(\frac{6}{9}\)=\(\frac{2}{3}\)

\(\frac{27}{36}=\frac{27:9}{36:9}=\frac{3}{4}\)

\(\frac{42}{63}=\frac{42:21}{63:21}=\frac{2}{3}\)

\(\frac{27}{36}=\frac{27:9}{36:9}=\frac{3}{4}\)

\(\frac{42}{63}=\frac{42:21}{63:21}=\frac{2}{3}\)

a: 44/77=4/7

b: 72/90=4/5

a,\(\dfrac{44}{77}=\dfrac{44:11}{77:11}=\dfrac{4}{7}\)

b\(\dfrac{72}{90}=\dfrac{72:9}{90:9}=\dfrac{8}{9}\)

\(a,\dfrac{44}{77}=\dfrac{44:11}{77:11}=\dfrac{4}{7}\\ b,\dfrac{72}{90}=\dfrac{72:9}{90:9}=\dfrac{8}{10}=\dfrac{4}{5}\)

\(\dfrac{6}{10}=\dfrac{3}{5};\dfrac{70}{90}=\dfrac{7}{9};\)\(\dfrac{96}{72}=\dfrac{4}{3}\)\(\dfrac{45}{35}=\dfrac{9}{7}\)

\(\dfrac{6}{10}=\dfrac{3}{5};\dfrac{70}{90}=\dfrac{7}{9};\dfrac{96}{72}=\dfrac{4}{3};\dfrac{45}{35}=\dfrac{9}{7}\)

6/10=3/5

70/90=7/9

96/72=4/3

45/35=9/7 nha

HT