Bài 1 trang 6 SGK Toán 5

Rút gọn các phân số: \(\dfrac{15}{25}\);  \(\dfrac{18}{27}\);    \(\dfrac{36}{64}\).

\(\dfrac{15}{25} = \dfrac{15:5}{25:5} = \dfrac{3}{5}\);

\(\dfrac{18}{27} = \dfrac{18 :9}{27:9} = \dfrac{2}{3}\);

\(\dfrac{36}{64}  = \dfrac{36:4}{64 : 4} = \dfrac{9}{16}\).