TÍNH NHANH :
a) -11/23 . 6/7+ 8/7 . -11/23 – 1/23
b) ( 337/-231 – 123/89 + 34 / 791) . ( 1/6 -1/8 – 1/24)
TÍNH NHANH : a) -11/23 . 6/7+ 8/7 . -11/23 – 1/23 b) ( 337/-231 – 123/89 + 34 / 791) . ( 1/6 -1/8 – 1/24)
By Gabriella
By Gabriella
TÍNH NHANH :
a) -11/23 . 6/7+ 8/7 . -11/23 – 1/23
b) ( 337/-231 – 123/89 + 34 / 791) . ( 1/6 -1/8 – 1/24)
Hướng dẫn trả lời:
`a) -11/23 . 6/7+ 8/7 . -11/23 – 1/23`
`=-11/23 . (6/7 +8/7)-1/23`
`=-11/23 . 2 -1/23`
`=-22/23-1/23`
`=-23/23`
`=-1`
`b) ( 337/-231 – 123/89 + 34 / 791) . ( 1/6 -1/8 – 1/24)`
`=( 337/-231 – 123/89 + 34 / 791) . ( 4/24 -3/24 – 1/24)`
`=( 337/-231 – 123/89 + 34 / 791) . 0`
`=0`
Đáp án:
$\frac{-11}{23}$.( $\frac{6}{7}$+ $\frac{8}{7}$)- $\frac{1}{23}$= $\frac{-11}{23}$.2- $\frac{1}{23}$ =-1
($\frac{377}{-231}$ -$\frac{123}{89}$ +$\frac{34}{791}$).0=0
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