\(\dfrac{20}{35}\text{=}\dfrac{4}{7}\)

\(\dfrac{5}{15}\text{=}\dfrac{1}{3}\)

\(\dfrac{12}{21}\text{=}\dfrac{4}{7}\)

\(\dfrac{8}{10}\text{=}\dfrac{4}{5}\)

\(\dfrac{20}{30}\text{=}\dfrac{2}{3}\)

\(\Rightarrow\left(\dfrac{20}{35}\text{=}\dfrac{12}{21}\text{=}\dfrac{4}{7}\right);\left(\dfrac{20}{30}\text{=}\dfrac{2}{3}\right).\)

4/7 = 12/21 = 20/35

HT

trong các phân số 6/15 ; 15/35 ; 20/12 ; 18/30, phân số bằng 3/5 là phân số 18/30

phân số =3/5 là:18/30

\(\frac{2}{5}=\frac{12}{30}=\frac{40}{100}\)

\(\frac{4}{7}=\frac{12}{21}=\frac{20}{35}\)

\(HokT\)

2/5=12/30; 4/7=12/21

            ht

B

B

a: 5/3=10/6=25/15=35/21

b: 5/7=35/49

6/15=12/30

4/5=16/20

c: 6=216/36=324/54=108/18

a)\(\dfrac{5}{3}=\dfrac{10}{6}=\dfrac{25}{15}=\dfrac{35}{21}\)

b)\(\dfrac{5}{7}=\dfrac{35}{49};\dfrac{6}{15}=\dfrac{12}{30};\dfrac{4}{5}=\dfrac{16}{20}\)

c) \(6=\dfrac{216}{36}=\dfrac{324}{54}=\dfrac{108}{18}\)

5/15 nhé

5/15

2/5=12/30=40/100

2/5=12/30=40/100

2/5=12/30=40/100

4/7=12/21=20/35

trả lời mk cho

co 21 / 35 =21 : 7 /35 : 7= 3/5

ta phai tim phan so a/b sao cho a/b = 3/5 va UCLN[a,b] =30

vi 3 va 5 la 2 so nguyen to cung nhau nen ta co :

tu do suy ra..........................................

ƯCLN(a,b)=30==>BCNN(a,b)=30

Từ đó bạn tự suy nghĩ nhé, cư sỷ lại ở đây ko tốt đâu!!! ;)