a)8/5-18/27=216/135-90/135=126/135

b)3/5-1/3=9/15-5/15=4/15(rút gọn p/s)

c)1/3-1/5=5/15-3/15=2/15

d)6/7-12/27=162/189-84/189=78/189

a) 8/5 - 18/27

= 8/5 - 2/3

= 24/15 - 10/15

= 14/15

b) 12/20 - 6/18

= 3/5 - 1/3

= 9/15 - 5/15

= 4/15

c) 8/24 - 5/25

= 1/3 - 1/5

= 5/15 - 3/15

= 2/15

d) 18/21 - 12/27

= 6/7 - 4/9

= 54/63 - 28/63

= 26/63

a: =8/5-2/3=24/15-10/15=14/15

12/20-6/18=3/5-1/3=9/15-5/15=4/15

b: 18/21-12/27=6/7-7/9=54/63-49/63=5/63

8/12-20/50=2/3-2/5=10/15-6/15=4/15

\(a,\dfrac{8}{5}-\dfrac{18}{27}=\dfrac{8}{5}-\dfrac{2}{3}=\dfrac{14}{15}\\ \dfrac{12}{20}-\dfrac{6}{18}=\dfrac{3}{5}-\dfrac{1}{3}=\dfrac{4}{15}\\ b,\dfrac{18}{21}-\dfrac{12}{27}=\dfrac{6}{7}-\dfrac{4}{9}=\dfrac{26}{63}\\ \dfrac{8}{12}-\dfrac{20}{50}=\dfrac{2}{3}-\dfrac{2}{5}=\dfrac{4}{15}\)

a) \(\dfrac{2}{5}-\dfrac{3}{15}\)

\(=\dfrac{2}{5}-\dfrac{3:3}{15:3}\)

\(=\dfrac{2}{5}-\dfrac{1}{5}\)

\(=\dfrac{1}{5}\)

b) \(\dfrac{9}{27}-\dfrac{2}{9}\)

\(=\dfrac{9:3}{27:3}-\dfrac{2}{9}\)

\(=\dfrac{3}{9}-\dfrac{2}{9}\)

\(=\dfrac{1}{9}\)

c) \(\dfrac{18}{24}-\dfrac{4}{8}\)

\(=\dfrac{18:6}{24:6}-\dfrac{4:2}{8:2}\)

\(=\dfrac{3}{4}-\dfrac{2}{4}\)

\(=\dfrac{1}{4}\)

d) \(\dfrac{6}{16}-\dfrac{10}{64}\)

\(=\dfrac{6\times2}{16\times2}-\dfrac{10:2}{64:2}\)

\(=\dfrac{12}{32}-\dfrac{5}{32}\)

\(=\dfrac{7}{32}\)

a: \(\dfrac{3}{9}\times\dfrac{5}{4}=\dfrac{5}{4}\times\dfrac{1}{3}=\dfrac{5\times1}{4\times3}=\dfrac{5}{12}\)

b: \(\dfrac{10}{15}\times\dfrac{3}{5}=\dfrac{3}{5}\times\dfrac{2}{3}=\dfrac{3\times2}{5\times3}=\dfrac{2}{5}\)

c: \(\dfrac{5}{8}\times\dfrac{4}{12}=\dfrac{5}{8}\times\dfrac{1}{3}=\dfrac{5}{3\times8}=\dfrac{5}{24}\)

d: \(\dfrac{9}{27}\times\dfrac{3}{21}=\dfrac{1}{7}\times\dfrac{1}{3}=\dfrac{1\times1}{7\times3}=\dfrac{1}{21}\)

\(\frac{3}{5}-\frac{5}{35}=\frac{21}{35}-\frac{5}{35}=\frac{16}{35}\)

\(\frac{18}{27}-\frac{2}{6}=\frac{1}{3}\)

\(\frac{15}{25}-\frac{3}{21}=\frac{16}{35}\)

\(\frac{24}{36}-\frac{6}{12}=\frac{1}{6}\)

tích đúng cho mk nhé

giúp mình với mọi người ơi

\(\dfrac{8}{24}-\dfrac{5}{25}=\dfrac{1}{3}-\dfrac{1}{5}=\dfrac{5}{15}-\dfrac{3}{15}=\dfrac{2}{15}\\ \dfrac{18}{21}-\dfrac{12}{27}=\dfrac{6}{7}-\dfrac{4}{9}=\dfrac{54}{63}-\dfrac{28}{63}=\dfrac{26}{63}\)

1/3-1/5= 2/15

6/7-4/9= 26/63

\(\frac{8}{5}-\frac{18}{27}\)

\(=\frac{8}{5}-\frac{2}{3}\)

\(=\frac{24}{15}-\frac{10}{15}\)

\(=\frac{14}{15}\)

\(\frac{12}{20}-\frac{6}{18}\)

\(=\frac{3}{5}-\frac{1}{3}\)

\(=\frac{9}{15}-\frac{5}{15}\)

\(=\frac{4}{15}\)

\(\frac{8}{24}-\frac{5}{25}\)

\(=\frac{1}{3}-\frac{1}{5}\)

\(=\frac{5}{15}-\frac{3}{15}\)

\(=\frac{2}{15}\)

\(\frac{18}{21}-\frac{12}{27}\)

\(=\frac{6}{7}-\frac{4}{9}\)

\(=\frac{54}{63}-\frac{28}{63}\)

\(=\frac{26}{63}\)

1)8/5-2/3=14/15

2)3/5-1/3=4/15

3)1/3-1/5=2/15

4)6/7-4/9=26/63

a: \(\dfrac{8}{18}+\dfrac{5}{3}=\dfrac{4}{9}+\dfrac{5}{3}=\dfrac{4}{9}+\dfrac{15}{9}=\dfrac{4+15}{9}=\dfrac{19}{9}\)

b: \(\dfrac{8}{24}+\dfrac{4}{48}=\dfrac{1}{3}+\dfrac{1}{12}=\dfrac{4}{12}+\dfrac{1}{12}=\dfrac{4+1}{12}=\dfrac{5}{12}\)

c: \(\dfrac{20}{15}-\dfrac{4}{45}=\dfrac{4}{3}-\dfrac{4}{45}=\dfrac{60}{45}-\dfrac{4}{45}=\dfrac{60-4}{45}=\dfrac{56}{45}\)

d: \(\dfrac{40}{32}-\dfrac{1}{2}=\dfrac{5}{4}-\dfrac{1}{2}=\dfrac{5-2}{4}=\dfrac{3}{4}\)

b: 12/20+6/18=3/5+1/3=9/15+5/15=14/15

c: 8/12+20/30=2/3+2/3=4/3

d: 10/12+12/36=5/6+2/6=7/6