AC gips em vứi ak! Viết vô vở (Nếu muốn)

Bài `1 :`

`a, ( 1/2 + 3/4 ) xx 4`

`= ( 2/4 + 3/4 ) xx 4`

`= 5/4 xx 4`

`= 5`

________________________

`b, 1/6 : 5/24 xx 2/3`

`= 1/6 xx 24/5 xx 2/3`

`= ( 1 xx 24 xx 2 )/( 6 xx 5 xx 3 )`

`= 8/15`

____________________________

`c, 1/2 xx 3/4 + 1/2 xx 1/4`

`= 1/2 xx ( 3/4 + 1/4 )`

`= 1/2 xx 1`

`= 1/2`

_____________________________

`d, 11/3 xx 26/7 - 26/7 - 8/3`

`= 26/7 xx ( 11/3 - 8/3 )`

`= 26/7 xx 1`

`= 26/7`

Bài `2 :`

`a, 2/3 xx 10/21 xx 3/2`

`= ( 2/3 xx 3/2 ) xx 10/21`

`= 1 xx 10/21`

`= 10/21`

`b, 22/5 xx 12 xx 5/22`

`= ( 22/5 xx 5/22 ) xx 12`

`= 1 xx 12`

`= 12`

`c, 2/5 xx 3/7 + 2/5 xx 4/7`

`= 2/5 xx ( 3/7 + 4/7 )`

`= 2/5 xx 1`

`= 2/5`

`d, 5/7 xx 21/4 xx 47/15 xx 0`

`= ( 5/7 xx 21/4 xx 47/15 ) xx 0`

`= 0`