Toán 1/(2.4) + 1/(4.6) + 1/(6.8) + 1/(8.10) (1-1/2)(1-1/3)…(1-1/10) 19/10/2021 By Peyton 1/(2.4) + 1/(4.6) + 1/(6.8) + 1/(8.10) (1-1/2)(1-1/3)…(1-1/10)
` 1/(2.4) + 1/(4.6) + 1/(6.8)+ 1/(8.10)` ` = 1/2 . ( 1/2 -1/4 +1/4-1/6+1/6-1/8 + 1/8-1/10)` ` = 1/2 . ( 1/2 -1/10) = 1/2 . 2/5=1/5` — `( 1- \frac{1}{2}) (1- \frac{1}{3}) (1- \frac{1}{4}) ….( 1- \frac{1}{10})` `= \frac{1}{2}. \frac{2}{3}. \frac{3}{4} ….\frac{9}{10}` ` = \frac{1.2.3….9}{2.3.4….10} = \frac{1}{10}` Trả lời
Đáp án: Giải thích các bước giải: 2×(1/2×4+1/4×6+1/6×8+1/8×10) =2/2×4+2/4×6+2/6×8+2/8×10 =1-1/4+1/4-1/6+1/6-1/8+1/8-1/10 =1-1/10 =9/10 (1-1/2)×(1-1/3)×….×(1-1/10) =1/2×2/3×….×9/10 =1/10 Trả lời
` 1/(2.4) + 1/(4.6) + 1/(6.8)+ 1/(8.10)`
` = 1/2 . ( 1/2 -1/4 +1/4-1/6+1/6-1/8 + 1/8-1/10)`
` = 1/2 . ( 1/2 -1/10) = 1/2 . 2/5=1/5`
—
`( 1- \frac{1}{2}) (1- \frac{1}{3}) (1- \frac{1}{4}) ….( 1- \frac{1}{10})`
`= \frac{1}{2}. \frac{2}{3}. \frac{3}{4} ….\frac{9}{10}`
` = \frac{1.2.3….9}{2.3.4….10} = \frac{1}{10}`
Đáp án:
Giải thích các bước giải:
2×(1/2×4+1/4×6+1/6×8+1/8×10)
=2/2×4+2/4×6+2/6×8+2/8×10
=1-1/4+1/4-1/6+1/6-1/8+1/8-1/10
=1-1/10
=9/10
(1-1/2)×(1-1/3)×….×(1-1/10)
=1/2×2/3×….×9/10
=1/10