\(\dfrac{64X15X9}{72X45X6}=\dfrac{8X8X5X3X9}{8X9X9X5X6}=\)\(\dfrac{24}{54}\)
Bài 5:
\(\dfrac{8\text{×}8\text{×}15\text{×}3\text{×}3}{8\text{×}9\text{×}3\text{×}15\text{×}3\text{×}2}\)\(=\)\(\dfrac{4}{9}\) (lần đầu dùng gõ phân số nên hơi chậm tí =')
Câu b e làm tương tự nhé
Bài 5:
\(a,\dfrac{64\times15\times9}{72\times45\times6}.\\ =\dfrac{8\times2\times4\times3\times5\times9}{8\times9\times9\times5\times3\times2}.\\ =\dfrac{4}{9}.\)
\(b,\dfrac{4242\times12\times15}{2121\times15\times20}.\\ =\dfrac{42\times101\times3\times4\times3\times5}{21\times101\times3\times5\times4\times5}.\\ =\dfrac{6}{5}.\)
