a: \(\dfrac{-8}{31}=\dfrac{-8\cdot101}{31\cdot101}=\dfrac{-808}{3131}\)

\(\dfrac{-789}{3131}=\dfrac{-789}{3131}\)

b: Thiếu phân số thứ hai rồi bạn

c: \(\dfrac{1}{n}=\dfrac{n+1}{n\left(n+1\right)}\)

\(\dfrac{1}{n+1}=\dfrac{n}{n\left(n+1\right)}\)

ai nhanh đúng thì đc 2 hoặc 3 k nhoa

a) \(\dfrac{-8}{31}=\dfrac{-8\cdot101}{31\cdot101}=\dfrac{-808}{3131}\)

\(\dfrac{-789}{3131}=\dfrac{-789}{3131}\)

c) \(\dfrac{1}{n}=\dfrac{n+1}{n\left(n+1\right)}\)

\(\dfrac{1}{n+1}=\dfrac{n}{n\left(n+1\right)}\)

a) \(-\dfrac{8}{31}=\dfrac{-8\cdot101}{31\cdot101}=\dfrac{-808}{3131}\)

\(\dfrac{-789}{3131}=\dfrac{-789}{3131}\)

c) \(\dfrac{1}{n}=\dfrac{n+1}{n\left(n+1\right)}\)

\(\dfrac{1}{n+1}=\dfrac{n}{n\left(n+1\right)}\)

a) \(-\dfrac{8}{31}=\dfrac{-8\cdot101}{31\cdot101}=\dfrac{-808}{3131}\)

\(\dfrac{-789}{3131}=\dfrac{-789}{3131}\)

b) \(\dfrac{11}{2^3\cdot3^4\cdot4^5}=\dfrac{11\cdot2^3\cdot5^3}{2^6\cdot3^4\cdot4^5\cdot5^3}=\dfrac{11000}{2^6\cdot3^4\cdot4^5\cdot5^3}\)

\(\dfrac{29}{2^2\cdot2^4\cdot5^3}=\dfrac{29\cdot3^4\cdot4^5}{2^6\cdot3^4\cdot4^5\cdot5^3}=\dfrac{2405376}{2^6\cdot3^4\cdot4^5\cdot5^3}\)

c) \(\dfrac{1}{n}=\dfrac{n+1}{n\left(n+1\right)}\)

\(\dfrac{1}{n+1}=\dfrac{n}{n\left(n+1\right)}\)

\(\frac{3}{5}=\frac{3\times8}{5\times8}=\frac{24}{40}\)

\(\frac{3}{8}=\frac{3\times5}{8\times5}=\frac{15}{40}\)

\(\frac{3}{10}=\frac{3\times4}{10\times4}=\frac{12}{40}\)

\(\frac{3}{2}=\frac{3\times20}{2\times20}=\frac{60}{40}\)

ghi thiếu bạn ơi

10000000000000000000000000000

\(\frac{3}{5}=\frac{24}{40};\frac{3}{8}=\frac{15}{40};\frac{3}{10}=\frac{12}{40};\frac{3}{2}=\frac{60}{40}\)

\(\frac{3}{5}=\frac{3\times8}{5\times8}=\frac{24}{40}\)

\(\frac{3}{8}=\frac{3\times5}{8\times5}=\frac{15}{40}\)

\(\frac{3}{10}=\frac{3\times4}{10\times4}=\frac{12}{40}\)

\(\frac{3}{2}=\frac{3\times20}{2\times20}=\frac{60}{40}\)

\(\frac{3}{5}=\frac{3\times8}{5\times8}=\frac{24}{40}\)

\(\frac{3}{8}=\frac{3\times5}{8\times5}=\frac{15}{40}\)

\(\frac{3}{10}=\frac{3\times4}{10\times4}=\frac{12}{40}\)

\(\frac{3}{2}=\frac{3\times20}{2\times20}=\frac{60}{40}\)

Bài 3 : 

a: \(MSC:12\\ \dfrac{4}{3}=\dfrac{4\times4}{3\times4}=\dfrac{16}{12};\dfrac{3}{4}=\dfrac{3\times3}{3\times4}=\dfrac{9}{12}\)

b: \(MSC:12\\ \dfrac{5}{4}=\dfrac{5\times3}{4\times3}=\dfrac{15}{12};\dfrac{5}{6}=\dfrac{5\times2}{6\times2}=\dfrac{10}{12}\)

c:\(MSC:24\\ \dfrac{3}{8}=\dfrac{3\times3}{8\times3}=\dfrac{9}{24};\dfrac{1}{6}=\dfrac{1\times2}{6\times2}=\dfrac{2}{12}\)

d: \(MSC:35\\ \dfrac{2}{5}=\dfrac{2\times7}{5\times7}=\dfrac{14}{35};\dfrac{4}{7}=\dfrac{4\times5}{7\times5}=\dfrac{20}{35}\)

Bài 3: 

a: 4/3=16/12

3/4=9/12

b: 5/4=30/24

5/6=20/24

c: 3/8=18/48

1/6=8/48

d: 2/5=14/35

4/7=20/35

Bài 4: 

a: 7/12=28/48

5/48=5/48

b: 4/100=4/100

8/25=32/100

20/35

_{Làm ơn giúp mình với !}