tính 1 cách hợp lí: a) $34.(-56)-134.(-56)$ b) $(34-14).(-5)+15.(-14-6)$ c) $135.3^{2}-3^{2}.130$ d) $159.(-37)-(-37).58-(-37)$ e) $(-42).(35-16)-35.(16-42)$ f) $703-140:(42+28)-17^{6}.17^{9}:17^{13}$

Đáp án:

`a)`

`34.(-56)-134.(-56)`

`=(-56).(34-134)`

`=-56.(-100)`

`=5600`

`d)`

`159.(-37)-(-37).58-(-37)`

`=159.(-37)-(-37).58-(-37)×1`

`=-37.(159-58-1)`

`=-37.100`

`=-3700`

`b)`

`(34-14).(-5)+15.(-14-6)`

`=34.(-5)-14.(-5)+15.(-14)+15.(-6)`

`=[34.(-5)+15.(-6)]+[-14.(-5)+15.(-14)]`

`=(-170-90)+[-14.(-5+15)]`

`=-260-14.10`

`=-260-140`

`=-400`

`e)`

`(-42).(35-16)-35.(16-42)`

`=-42.35-42.(-16)-35.16+9-35.(-42)`

`=[-42.35-35.(-42)]+[-42.(-16)-35.16]`

`=(-42.35-35.42)+[-16.(-42+35)]`

`=0-16.(-7)`

`=112`

`c)`

`135.3^(2)-3^(2).130`

`=3^(2)(135-130)`

`=3^(2).5`

`=9.5`

`=45`

`f)`

`703-140:(42+28)-17^(6).17^(9):17^13`

`=730-140:70-17^(6+9-13)`

`=730-2-289`

`=439`