Question

Câu 2: a, Qui đồng mẫu số các phân số sau rồi sắp xếp theo thứ tự tăng dần: \(\dfrac{3}{5}\);\(\dfrac{3}{4}\);\(\dfrac{7}{12}\)

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b, So sánh hai phân số sau : \(\dfrac{12}{15}\)và \(\dfrac{1212}{1515}\)

Answer 1

a, MSC : \(60\)

\(\dfrac{3}{5}=\dfrac{3.12}{5.12}=\dfrac{36}{60}\\ \dfrac{3}{4}=\dfrac{3.15}{4.15}=\dfrac{45}{60}\\ \dfrac{7}{12}=\dfrac{7.5}{12.5}=\dfrac{35}{60}\\ 35< 36< 45\\ =>\dfrac{7}{12}< \dfrac{3}{5}< \dfrac{3}{4}\\ \dfrac{7}{12};\dfrac{3}{5};\dfrac{3}{4}\\ \)

b, 

\(\dfrac{1212}{1515}=\dfrac{1212:101}{1515:101}=\dfrac{12}{15}\)

Answer 2

`a ) MSC : 60`

`3/4=45/60`

`3/5=36/60`

`7/12=35/60`

Sắp xếp : `7/12 < 3/5 < 3/4`

`b) 1212/1515 = ( 1212 : 101 ) / ( 1515 : 101) = 12/15`

`12/15 = 12/15` hay `12/15 = 1212/1515`