Question

Tính nhanh : 

   \(\frac{1}{6}x\frac{2}{5}x\frac{25}{7}\)

 * Lư ý : Tính nhanh

Answer 1

\(\frac{1\times2\times25}{6\times5\times7}\)\(=\frac{1\times2\times5\times5}{2\times3\times5\times7}=\frac{5}{3\times7}=\frac{5}{21}\)

Answer 2

1/6×2/5×25/7=

rut gon:25(tử)÷5 (mâu), 6 (tử)÷2 (mau)

được

1/3×1/1×5/7=5/21