Mọi người ơi ️

Hãy giúp mình bài này với ạ

`1.`

`a) 1/2 xx 2/3 xx 3/4 = (1 xx 2 xx 3)/(2 xx 3 xx 4) = 6/24 = 1/4`

`b) 7/8 xx 8/9 xx 9/10 = (7 xx 8 xx 9)/(8 xx 9 xx 10) = 504/720 = 7/10`

`c) 5/14 xx 7/15 xx 28/7 = (5 xx 7 xx 28)/(14 xx 15 xx 7) = 980/1470 = 98/147` 

`d) 2 × 1/2 × 3 × 1/3 × 4 × 1/4 × 5 × 1/5 = ( 2 × 1/2 ) × ( 3 × 1/3 ) × ( 4 × 1/4 ) × ( 5 × 1/5 ) = 2/2 × 3/3 × 4/4 × 5/5 = 1 xx 1 xx 1 xx 1 xx 1 = 1`

`2.`

`a) ( 2/3 xx 3/2 ) xx 10/21 = 6/6 xx 10/21 = 1 xx 1021 = 1021`

`b) ( 22/5 xx 5/22 ) xx 12 = 110 xx 12 = 1 xx 12 = 12`

`c) ( 7/2 xx 2/7 ) xx 23/81 = 14/14 xx 23/81 = 1 xx 23/81 = 23/81`

`d) ( 11/8 xx 8/3 ) xx ( 26/7 - 26/7) = 88/24 xx 1/7 = 88/168 = 11/21`

`3.`

`a) ( 1/2 + 3/4 ) xx 4 = 4/8 + 6/8 = 10/8 xx 4 = 40/8 = 5/1 =5` 

`b) 1/2 xx 3/4 + 1/2 xx 1/4 = 3/8 + 1/8 = 4/8 = 1/2`

`c) ( 5/7 - 1/14 ) xx 7 = ( 10/14 - 1/14 ) xx 7 = 9/14 - 7 = 63/14 = 9/2` 

`d) ( 11/3 xx 8/3 ) xx ( 26/7 - 26/7 ) = 88/3 xx 1/7 = 88/3 xx 7 = 616/3`

`color{red}{@Duyen5675}`

Mong bạn cho mik `5` sao + Cảm ơn + Ctlhn