\(=\dfrac{5}{8}\times\dfrac{6}{7}=\dfrac{5\times3}{4\times7}=\dfrac{15}{28}\)

= 15/28

\(\dfrac{15}{28}\)

\(\dfrac{3}{2}\)

\(\dfrac{8}{10}+\dfrac{7}{10}=\dfrac{15}{10}=\dfrac{3}{2}\)

\(=\dfrac{8}{10}+\dfrac{7}{10}=\dfrac{3}{2}\)

\(=\dfrac{2}{3}\times\left(\dfrac{4}{10}+\dfrac{1}{5}\right)\\ =\dfrac{2}{3}\times\dfrac{3}{5}=\dfrac{2}{5}\)

\(\dfrac{2}{3}\times\left(\dfrac{4}{10}+\dfrac{1}{5}\right)=\dfrac{2}{3}\times\left(\dfrac{4}{10}+\dfrac{2}{10}\right)=\dfrac{2}{3}\times\dfrac{6}{10}=\dfrac{2}{3}\times\dfrac{3}{5}=\dfrac{6}{15}=\dfrac{2}{5}\)

2/5

\(=\dfrac{1}{12}\cdot5=\dfrac{5}{12}\)

1/60

\(\dfrac{1}{3}\times\dfrac{1}{4}\times\dfrac{1}{5}=\dfrac{1}{60}\)

1/3.1/4.1/5

=1/12.1/5

=1/60

1

\(\dfrac{4}{7}\times\dfrac{7}{4}=1\) 

(rút gọn chéo)

1

5/7

5/7

\(\dfrac{25}{35}=\dfrac{25:5}{35:5}=\dfrac{5}{7}\)

1

\(\dfrac{2}{3}\times\dfrac{3}{2}=1\)

(rút gọn chéo)

1

1 điểm là dg thi hả e

Sau 2 giờ chạy được 3/8+2/7=37/56(quãng đường)