a) \(\frac{3}{5}\times y+\frac{1}{2}:\frac{5}{3}-\frac{5}{4}=\frac{1}{2}\times\frac{1}{3}\)

\(\Rightarrow\frac{3}{5}\times y+\frac{3}{10}-\frac{5}{4}=\frac{1}{6}\)

\(\Rightarrow\frac{3}{5}\times y+\left(-\frac{19}{20}\right)=\frac{1}{6}\)

\(\Rightarrow\frac{3}{5}\times y=\frac{67}{60}\)

\(\Rightarrow y=\frac{67}{36}\)

b) \(\frac{4}{5}:y+\frac{1}{4}\times\frac{1}{6}-\frac{1}{2}=\frac{1}{3}\times\frac{5}{2}\)

\(\Rightarrow\frac{4}{5}:y+\frac{1}{24}-\frac{1}{2}=\frac{5}{6}\)

\(\Rightarrow\frac{4}{5}:y+\left(-\frac{11}{24}\right)=\frac{5}{6}\)

\(\Rightarrow\frac{4}{5}:y=\frac{5}{6}+\frac{11}{24}=\frac{31}{24}\)

\(\Rightarrow y=\frac{4}{5}:\frac{31}{24}=\frac{96}{155}\)

c) \(\frac{3}{5}\times y-\frac{4}{5}:3+\frac{1}{12}=\frac{3}{2}+\frac{1}{5}\)

\(\Rightarrow\frac{3}{5}\times y-\frac{4}{15}+\frac{1}{12}=\frac{17}{10}\)

\(\Rightarrow\frac{3}{5}\times y-\frac{4}{15}=\frac{97}{60}\)

\(\Rightarrow\frac{3}{5}\times y=\frac{113}{60}\)

\(\Rightarrow y=\frac{113}{36}\)

a) \(\frac{27}{36}=\frac{3}{4}\)

b) \(\frac{45}{60}=\frac{3}{4}\)

c) \(\frac{2}{4}=\frac{1}{2}\)

d) \(\frac{10}{12}=\frac{5}{6}\)

e) \(\frac{112}{252}=\frac{4}{9}\)

Đúng nha bạn !!@@

\(\frac{1}{3}+\frac{3}{4}x\frac{5}{9}=\frac{1}{3}+\frac{5}{12}=\frac{3}{4}\)

\(\frac{7}{12}-\frac{5}{4}x\frac{2}{15}=\frac{7}{12}-\frac{1}{6}=\frac{5}{12}\)

\(y+\frac{1}{4}=\frac{7}{8}-\frac{3}{8}=y+\frac{1}{4}=\frac{1}{2}=\frac{1}{2}-\frac{1}{4}=\frac{1}{4}\)

\(y-\frac{5}{12}=\frac{2}{3}-\frac{1}{4}=y-\frac{5}{12}=\frac{5}{12}=\frac{5}{12}+\frac{5}{12}=\frac{5}{6}\)

\(\frac{12}{7}xy=\frac{16}{21}=\frac{16}{21}:\frac{12}{7}=\frac{4}{9}\)

\(\frac{5}{4}:y=\frac{7}{12}=\frac{5}{4}:\frac{7}{12}=\frac{15}{7}\)

bai toan nay ? 

    Bài 1 :

    A = 1 - 1/2 + 1/2 - 1/4 + 1/4 - 1/8 + 1/8 - 1/16 + ... + 1/32 - 1/64

    A = 1 - 1/64

    A = 63/64

=3

hok tốt

12/3 x Y = 12/1

           Y = 12/1 : 12/3

           Y = 3

\(\frac{1}{6}+\frac{5}{6}=\frac{6}{6}=1\)

\(\frac{25}{5}+\frac{2}{6}=\frac{150}{30}+\frac{10}{30}=\frac{160}{30}=\frac{32}{6}=\frac{16}{3}\)

\(\frac{12}{5}+\frac{6}{9}=\frac{108}{45}+\frac{30}{45}=\frac{138}{45}\)

\(\frac{11}{6}\)

\(\frac{16}{3}\)

\(\frac{46}{3}\)

1. n = 15;16;17;18;19;20;21;22;23;24 

2. y = 20

Bạn tự đăng câu hỏi thì bạn phải tự trả lời chứ.

k nha !

Ta có \(x.a=b\)

\(x=b:a\)

Do đó \(-\frac{3}{5}.x=\frac{5}{6}\)

\(x=\frac{5}{6}:\frac{-3}{5}\)

\(x=-\frac{1}{2}\)

Tương tự 

2. \(x=\frac{6}{8}:\frac{2}{4}=\frac{3}{2}\)

Bạn tự làm câu 3

1.\(\frac{-3}{5}\).x=\(\frac{5}{6}\)

x=\(\frac{5}{6}\):\(\frac{-3}{5}\)

x=\(\frac{-25}{18}\)

2.\(\frac{2}{4}\):x=\(\frac{6}{8}\)

\(\frac{1}{2}\):x=\(\frac{3}{4}\)

x=\(\frac{1}{2}\):\(\frac{3}{4}\)

x=\(\frac{2}{3}\)

3.\(\frac{67}{89}\).x=\(\frac{12}{13}\)

x=\(\frac{12}{13}\):\(\frac{67}{89}\)

x=\(\frac{1068}{871}\)

K MIK NHÉ