tính bằng 2 cách (6/11+ 5/11) x 3/7 3/5 x 7/9 – 3/5 x 2/9 ( 6/7 -4/17 ) :2/5 8/15: 2/11 + 7/15 : 2/11

0 bình luận về “tính bằng 2 cách (6/11+ 5/11) x 3/7 3/5 x 7/9 – 3/5 x 2/9 ( 6/7 -4/17 ) :2/5 8/15: 2/11 + 7/15 : 2/11”

1.  

   Giải thích các bước giải:

   a)C1:

   (`6/11`+ `5/11`) x `3/7`

   =1 x `3/7`

   =`3/7`

   a)C2:

   (`6/11`+ `5/11`) x `3/7`

   =`18/77`+`15/77`

   =`33/77`=`3/7`

   b)C1:

   `3/5` x `7/9` – `3/5` x `2/9`

   =`21/45`-`6/45`

   =`15/45`=`1/3`

   b)C2:

   `3/5` x `7/9` – `3/5` x `2/9`

   =`3/5` x (`7/9`-`2/9`)

   =`3/5` x `5/9` = `1/3`

   c)C1:

   ( `6/7` -`4/17` ) :`2/5`

   =`74/119` x `5/2` 

   =`185/119`

   c)C2:

   ( `6/7` -`4/17` ) :`2/5`

   =`15/7`  – `10/17`

   =`185/119`

   d)C1:

   `8/15`:`2/11` + `7/15` : `2/11`

   =`88/30`+`77/30`

   =`165/30`=`11/2`

   d)C2:

   `8/15`:`2/11` + `7/15` : `2/11`

   =(`8/15`+`7/15`):`2/11`

   =1 x `11/2`=`11/2`

   Bình luận

2. 1. (6/11+ 5/11) x 3/7=(11/11)x3/7=3/7

   (6/11+ 5/11) x 3/7= 6/11 x 3/7 + 5/11×3/7=18/77 + 15/77=3/7

   2. 3/5 x 7/9 – 3/5 x 2/9=3/5 x ( 7/9 – 2/9 )=3/5 x 5/9 =3/9

   3/5 x 7/9 – 3/5 x 2/9= 7/15 – 2/15= 3/9

   3. ( 6/7 -4/17 ) :2/5= 2/17:2/5=5/17

   ( 6/7 -4/17 ) :2/5=6/7: 2/5- 4/7 : 2/5=15/7- 10/7=5/7

   4. 8/15: 2/11 + 7/15 : 2/11=44/15+ 77/30=11/2

   8/15: 2/11 + 7/15 : 2/11= (8/15+ 7/15):2/11=15/15:2/11=11/2

    

   Bình luận