thực hiện phép tính
a) 1/2 . ( 2/9 + 3/7 – 5/27 )
b) 1/3 . 5/7 – 7/27 . 36/14
thực hiện phép tính a) 1/2 . ( 2/9 + 3/7 – 5/27 ) b) 1/3 . 5/7 – 7/27 . 36/14
By Remi
By Remi
thực hiện phép tính
a) 1/2 . ( 2/9 + 3/7 – 5/27 )
b) 1/3 . 5/7 – 7/27 . 36/14
`a,`
`1/2 . (2/9 + 3/7 – 5/27)`
`= 1/2 . (41/63 – 5/27)`
`= 1/2 . 88/189`
`= (1.88)/(2.189)`
`= 244/189`
`b,`
`1/3 . 5/7 – 7/27 . 36/14`
`= 5/21 – 2/3`
`= 5/21 – 14/21`
`= (5 – 14)/21`
`= (-3)/7`
`a)` `1/2` `.` `( 2/9 + 3/7 – 5/27 )`
`1/2` `.` `( 42/189 + 81/189 – 35/189 )`
`1/2` `.` `88/189`
`88/378`
`44/189`
`b)` `1/3` `.` `5/7` `-` `7/27` `.` `36/14`
`5/21` `-` `7/27` `.` `18/7`
`5/21` `-` `126/189`
`45/189` `-` `126/189`
`-3/7`
$#UMR#$