( 1- 1/4) x ( 1-1/9) x ( 1-1/25) x ( 1- 1/36) x ( 1-1/49) =???
cho cách làm và đáp án ạ
( 1- 1/4) x ( 1-1/9) x ( 1-1/25) x ( 1- 1/36) x ( 1-1/49) =??? cho cách làm và đáp án ạ
By Eloise
By Eloise
( 1- 1/4) x ( 1-1/9) x ( 1-1/25) x ( 1- 1/36) x ( 1-1/49) =???
cho cách làm và đáp án ạ
Đáp án:
`(1- 1/4) × (1 – 1/9) × (1 – 1/25) × (1 – 1/36) × (1-1/49)`
`= 3/4 × 8/9 × 24/25 × 35/36 × 48/49`
`= (3 × 8 × 24 × 35 × 48)/(4 × 9 × 25 × 36 × 49)`
`= (3 × 4 × 2 × 8 × 3 × 5 × 7 × 8 × 6)/(4 × 3 × 3 × 5 × 5 × 2 × 3 × 6 × 7 × 7)`
`= ( 8 × 8 )/( 5 × 3 × 7)`
`= 64/105`
`text{promax123}`
Đáp án :
`64/105`
Giải thích :
( 1 – `1/4` ) x ( 1 – `1/9` ) x ( 1 – `1/25` ) x ( 1 – `1/36` ) x ( 1 – `1/49` )
= ( `4/4` – `1/4` ) x ( `9/9` – `1/9` ) x ( `25/25` – `1/25` ) x ( `36/36` – `1/36` ) x ( `49/49` – `1/49` )
= `3/4` x `8/9` x `24/25` x `35/36` x `48/49`
= `2/3` x `14/15` x `48/49`
= `28/45` x `48/49`
= `64/105`