đáp án là B

ý B nhé bạmn

50/25 + 4/5 = 50/25 + 20/25 = 70/25 = 14/5

\(\frac{50}{25}+\frac{4}{5}=\frac{10}{5}+\frac{4}{5}=\frac{14}{5}\)

12/60 , 7/12 , 3/5 , 25/25 , 5/4

12/60 ; 7/12 ; 3/5 ; 25/25 ; 5/4

cộng các phấn số cùng mẫu trước

\(\frac{12}{25}+\frac{3}{5}+\frac{13}{25}=\left(\frac{12}{25}+\frac{13}{25}\right)+\frac{3}{5}=1+\frac{3}{5}=\frac{8}{5}\)

\(\frac{3}{2}+\frac{2}{3}+\frac{4}{3}=\left(\frac{2}{3}+\frac{4}{3}\right)+\frac{3}{2}=2+\frac{3}{2}=\frac{7}{2}\)

\(\frac{3}{5}+\frac{7}{5}+\frac{3}{4}=\left(\frac{3}{5}+\frac{7}{5}\right)+\frac{3}{4}=2+\frac{3}{4}=\frac{11}{4}\)

\(\frac{25}{32}\cdot\frac{8}{50}.\frac{4}{3}.\frac{5}{10}=\frac{1}{12}\)

\(\frac{25}{32}\times\frac{8}{50}\times\frac{4}{3}\times\frac{5}{10}\)

\(=\frac{5\times5\times8\times4\times5}{8\times4\times5\times5\times2\times3\times5\times2}\)

\(=\frac{1}{12}\)

k mk nha

thank you very much

a )

2 / 3 + 5 / 4 = 8 / 12 + 15 / 12 = 23 / 12

b )

15 / 25 + 6 / 21 = 3 / 5 + 2 / 7 

                       = 21 / 35 + 10 / 35

                       = 31 / 35

c ) 

4 / 3 - 11 / 15 = 20 / 15 - 11 / 15

                    = 9 / 15

d )

12 / 10 - 2 / 5 = 12 / 10 - 4 / 10

                    = 8 / 10

                    = 4 / 5

a=23/12

b=31/35

c=3/5

d=4/5

=1 PHAN 12 NHA

KIK MÌNH NHA

Làm từng cái nhé: \(\frac{25}{32}\times\frac{8}{50}=\frac{1}{4}\times\frac{1}{2}=\frac{1}{8}\)

Tiếp: \(\frac{1}{8}\times\frac{4}{3}=\frac{1}{2}\times\frac{1}{3}=\frac{1}{6}\)

Tiếp: \(\frac{5}{10}=\frac{1}{2}\)

Còn lại: \(\frac{1}{2}\times\frac{1}{6}=\frac{1}{12}\)

a) \(\frac{12}{25}+\frac{3}{5}+\frac{13}{25}\)

= \(\left(\frac{12}{25}+\frac{13}{25}\right)+\frac{3}{5}\)

= \(\frac{25}{25}+\frac{3}{5}\)

= \(1+\frac{3}{5}\)

= \(\frac{1}{1}+\frac{3}{5}\)

= \(\frac{5}{5}+\frac{3}{5}\)

= \(\frac{8}{5}\)

bài này tớ mà làm sai thì tớ ......................ko lm người........-_-

a) \(\frac{12}{25}+\frac{3}{5}+\frac{13}{25}\)

= \(\frac{12}{25}+\frac{15}{25}+\frac{13}{25}\)

= \(\frac{12+15+13}{25}\)

= \(\frac{40}{25}\)

= \(\frac{8}{5}\)

b) \(\frac{3}{2}+\frac{2}{3}+\frac{4}{3}\)

= \(\frac{9}{6}+\frac{4}{6}+\frac{8}{6}\)

= \(\frac{9+4+8}{6}\)

= \(\frac{21}{6}\)

= \(\frac{7}{2}\)

giúp tôi với

\(\frac{15}{2}:\frac{7}{4}-\frac{25}{18}:\frac{35}{6}\) 

= \(\frac{5}{21}-\frac{5}{21}\)

= 0

= 0 nha bạn