A=3/1.4 + 3/4.7 + …. + 3/40.43 < Tuyển thành viên , hạt cát nhỏ > 18/07/2021 Bởi Piper A=3/1.4 + 3/4.7 + …. + 3/40.43 < Tuyển thành viên , hạt cát nhỏ >
`3/( 1 . 4 ) + 3/( 4 . 7 ) + ….. + 3/( 40 . 43 )` `= 1/1 – 1/4 + 1/4 – 1/7 + …… + 1/40 – 1/43` `= 1 – 1/43` `= 43/43 – 1/43 = 42/43` Bình luận
$\frac{3}{1.4}$ + $\frac{3}{4.7}$ + … + $\frac{3}{40.43}$ = 1 – $\frac{1}{4}$ + $\frac{1}{4}$ – $\frac{1}{7}$ +… + $\frac{1}{40}$ – $\frac{1}{43}$ = 1 – $\frac{1}{43}$ = $\frac{42}{43}$ Vậy $\frac{3}{1.4}$ + $\frac{3}{4.7}$ + … + $\frac{3}{40.43}$= $\frac{42}{43}$ Bình luận
`3/( 1 . 4 ) + 3/( 4 . 7 ) + ….. + 3/( 40 . 43 )`
`= 1/1 – 1/4 + 1/4 – 1/7 + …… + 1/40 – 1/43`
`= 1 – 1/43`
`= 43/43 – 1/43 = 42/43`
$\frac{3}{1.4}$ + $\frac{3}{4.7}$ + … + $\frac{3}{40.43}$
= 1 – $\frac{1}{4}$ + $\frac{1}{4}$ – $\frac{1}{7}$ +… + $\frac{1}{40}$ – $\frac{1}{43}$
= 1 – $\frac{1}{43}$
= $\frac{42}{43}$
Vậy $\frac{3}{1.4}$ + $\frac{3}{4.7}$ + … + $\frac{3}{40.43}$= $\frac{42}{43}$