Tính:
a) \(7285 \times 302 \) \(35,48\times 4,5\) \(21,63 \times 2,04\) \(92,05\times 0,05\)
b) \(\displaystyle{9 \over {15}} \times {{25} \over {36}}\) \(\displaystyle{8 \over {27}} \times 9\)
a)
b)
\(\displaystyle{9 \over {15}} \times {{25} \over {36}} = \dfrac{9\times 25}{15 \times 36}=\dfrac{9\times5 \times 5}{5\times 3 \times 9 \times 4} = \dfrac{5}{12}\)
\(\displaystyle{8 \over {27}} \times 9=\dfrac{8\times9}{27 } = \dfrac{8\times9}{9 \times 3 }=\dfrac{8}{3}\)
-- Mod Toán lớp 5