1)
a) \(\dfrac{4}{5}\times\dfrac{6}{7}\)
\(=\dfrac{4\times6}{5\times7}\)
\(=\dfrac{24}{35}\)
b) \(\dfrac{2}{9}\times\dfrac{1}{2}\)
\(=\dfrac{2\times1}{9\times2}\)
\(=\dfrac{1}{9}\)
c) \(\dfrac{1}{2}\times\dfrac{8}{3}\)
\(=\dfrac{1\times8}{2\times3}\)
\(=\dfrac{4}{3}\)
d) \(\dfrac{1}{8}\times\dfrac{1}{7}\)
\(=\dfrac{1\times1}{8\times7}\)
\(=\dfrac{1}{56}\)
Bài 2:
a: \(\dfrac{2}{6}\cdot\dfrac{7}{5}=\dfrac{1}{3}\cdot\dfrac{7}{5}=\dfrac{7}{15}\)
b: \(\dfrac{11}{9}\cdot\dfrac{5}{10}=\dfrac{11}{9}\cdot\dfrac{1}{2}=\dfrac{11}{9\cdot2}=\dfrac{11}{18}\)
c: \(\dfrac{3}{9}\cdot\dfrac{6}{8}=\dfrac{1}{3}\cdot\dfrac{3}{4}=\dfrac{1}{4}\)
Bài 3:
Diện tích hình chữ nhật là:
\(\dfrac{6}{7}\cdot\dfrac{3}{5}=\dfrac{6\cdot3}{7\cdot5}=\dfrac{18}{35}\left(m^2\right)\)
3) Diện tích của hình chữ nhật là:
\(\dfrac{6}{7}\times\dfrac{3}{5}=\dfrac{18}{35}\left(m^2\right)\)
ĐS: ...
