Question

tính nhanh

9*8*7*5*20/7*5*9*10*           *⇒là dấu nhân

5*7*9*39/35*13*18*

Answer 1

\(\dfrac{9\cdot8\cdot7\cdot5\cdot20}{7\cdot5\cdot9\cdot10}=\dfrac{8\cdot20}{10}=8\cdot2=16\)

\(\dfrac{5\cdot7\cdot9\cdot39}{35\cdot13\cdot18}=\dfrac{9}{18}\cdot\dfrac{39}{13}=\dfrac{3}{2}\)

Answer 2

9×8×7×5×20/7×5×9×10

= 8×2

= 16

5×7×9×39/35×13×18

= 3/2