60 điểm đó Rút gọn biểu thức:$A=(1-\dfrac{1}{21})(1-\dfrac{1}{28})…..(1-\dfrac{1}{1326})$ Giúp với 01/07/2021 Bởi Parker 60 điểm đó Rút gọn biểu thức:$A=(1-\dfrac{1}{21})(1-\dfrac{1}{28})…..(1-\dfrac{1}{1326})$ Giúp với
A=(1-$\frac{1}{21}$) (1-$\frac{1}{28}$)….(1- $\frac{1}{1326}$ ) A=$\frac{20}{21}$ $\frac{27}{28}$ ….$\frac{1325}{1326}$ A=($\frac{20}{21}$ $\frac{27}{28}$ ….$\frac{1325}{1326}$ ).2 A=$\frac{40}{42}$ $\frac{54}{56}$…… $\frac{2650}{2652}$ A=$\frac{5.8}{6.7}$ $\frac{6.9}{7.8}$ …..$\frac{50.53}{51.52}$ A=$\frac{5.53}{7.51}$ A=$\frac{265}{357}$ #HỌC TỐT #NOT COPPY Bình luận
Lời giải: `A=(1-1/21)(1-1/28)….(1-1/1326)` `=20/21. 27/28. ….1325/1326` `=40/42 . 54/56….2650/2652` `=(5.8)/(6.7).(6.9)/(7.8)….(50.53)/(51.52)` `=(5.8.6.9…50.53)/(6.7.7.8…51.52)` `=(5.6.7…50)/(6.7.8…51) . (8.9…52)/(7.8…52)` `=5/51. 53/7` `=265/357` Bình luận
A=(1-$\frac{1}{21}$) (1-$\frac{1}{28}$)….(1- $\frac{1}{1326}$ )
A=$\frac{20}{21}$ $\frac{27}{28}$ ….$\frac{1325}{1326}$
A=($\frac{20}{21}$ $\frac{27}{28}$ ….$\frac{1325}{1326}$ ).2
A=$\frac{40}{42}$ $\frac{54}{56}$…… $\frac{2650}{2652}$
A=$\frac{5.8}{6.7}$ $\frac{6.9}{7.8}$ …..$\frac{50.53}{51.52}$
A=$\frac{5.53}{7.51}$
A=$\frac{265}{357}$
#HỌC TỐT
#NOT COPPY
Lời giải:
`A=(1-1/21)(1-1/28)….(1-1/1326)`
`=20/21. 27/28. ….1325/1326`
`=40/42 . 54/56….2650/2652`
`=(5.8)/(6.7).(6.9)/(7.8)….(50.53)/(51.52)`
`=(5.8.6.9…50.53)/(6.7.7.8…51.52)`
`=(5.6.7…50)/(6.7.8…51) . (8.9…52)/(7.8…52)`
`=5/51. 53/7`
`=265/357`