`d) (-7)/9 . 3/11 + (-7)/9 . 8/11 + 1 7/9`

`= (-7)/9 . ( 3/11 + 8/11) + 1 7/9`

`= (-7)/9 . 1 + 1 7/9`

`= -7/9 + 1 7/9`

`= 1`

``

`e) 7/35 . 10/19 + 7/35 . 9/19 - 2/35`

`= 7/35 . ( 10/19 + 9/19) - 2/35`

`= 7/35 . 1 - 2/35`

`= 7/35 - 2/35`

`= 1/7`

``

`f) (-25) . 125 . 4 . (-8) . (-17)`

`= [ (-25) . 4] . [ 125 . (-8) . (-17)`

`= -100 .  (-1000) . (-17)`

`= -17 00 000`

``

`g) (-3)/4 + 2/7 + (-1)/4 + 3/5 + 5/7`

`= ((-3)/4 + (-1)/4) + ( 2/7 + 5/7) + 3/5`

`= (-1) + 1 + 3/5`

`= 0 + 3/5`

`= 3/5`

``

`h) 7/19 . 8/11 + 7/19 . 3/11 - 12/19`

`= 7/19 . ( 8/11 + 3/11) - 12/19`

`= 7/19 . 1 - 12/19`

`= 7/19 - 12/19`

`= -5/19`

Đáp án+ Giải thích các bước giải:

Câu 1: -7/9.3/11+-7/9.8/11+ 1 7/9

= -7/9.(3/11+8/11)

= -7/9.1

= -7/9

Câu 2: 7/35.10/19+7/35.9/19-2/35

= 7/35.(10/19+9/19)-2/35

= 7/35.1-2/35

= 7/35-2/35

=1/7

Câu 3: (-25).125.4.(-8).(-17) 

= -3125.4.(-8).(-17)

= -12500.(-8).(-17)

= 100000.(-17)

= -1.700.000

Câu 4: -3/4+2/7+-1/4+3/5+5/7

= (-3/4+-1/4).(2/7+5/7)+3/5

= -1.1+3/5

= -1+3/5

= -2/5

Câu 5: 7/19.8/11+7/19.3/11-12/19

= 7/19.(8/11+3/11).(8/11+3/11)-12/19

= 7/19.1.1-12/19

= 7/19-12/19

= -5/19

Đáp án đây nha bạn!