thuc hien phep tinh a.4/5+3/5:3-7/8 b.(2/3+3/4).(5/7+5/14) c.3/7.1/5+3/7.3/5+3/7 d.7/11+(3/7+-7/11) giup em em vote 5 sao ak

Đáp án:

`a)4/5+3/5:3-7/8`

`=4/5+1/5-7/8`

`=1-7/8`

`=1/8`

`b)(2/3+3/4).(5/7+5/14)`

`=(8/12+9/12).(10/14+5/14)`

`=17/12. 15/14`

`=(17.15)/(12.14)`

`=85/56`

`c)3/7. 1/5+3/7. 3/5+3/7`

`=3/7.(1/5+3/5+1)`

`=3/7 . 9/5`

`=27/35`

`d)7/11+(3/7+(-7)/11)`

`=7/11+3/7-7/11`

`=(7/11-7/11)+3/7`

`=0+3/7`

`=3/7`