-2,902,900

tính hợp lí

  -145.(13-57)+57.(10-145)

=-145.(-44)+57.(-135)

=6380+(-7695)
=-1315

-145.(13-57)+57.(10-145)=(-145).(-44)+57.(-135)=6380+(-7695)=-1315

a) \(\left(-17\right)\cdot32+17\cdot\left(-68\right)-17\)

\(=17\cdot\left(-32-68-1\right)\)

\(=17\cdot\left(-101\right)\)

\(=17\cdot\left(-100-1\right)\)

\(=-1700-17\)

\(=-1717\)

b) \(25\cdot\left(34-89\right)+25\cdot89\)

\(=25\cdot\left(34-89+89\right)\)

\(=25\cdot34\)

\(=850\)

c) \(-145\cdot\left(13-57\right)+57\cdot\left(10-145\right)\)

\(=-145\cdot13+145\cdot57+57\cdot10-145\cdot57\)

\(=-145\cdot\left(13+57\right)+57\cdot\left(145+10\right)\)

\(=-145\cdot70+57\cdot155\)

\(=-10150+8835\)

\(=-1315\)

`@` `\text {Ans}`

`\downarrow`

`a)`

\((- 17) . 32 + 17 . (- 68) – 17 \)

`= (-17). (32 + 68 + 1) `

`= (-17). 101`

`= -1717`

`b)`

\(25 . (34 – 89) + 25 . 89\)

`= 25. (34 - 89 + 89)`

`= 25. 34`

`= 850`

`c)`

\(– 145. (13 – 57) + 57. (10 – 145)\)

`= (-145). 13 - (-145). 57 + 57.10 + 57. (-145)`

`= (-145). (13 - 57 + 57) + 57.10`

`= (-145). 13 + 570`

`= -1885 + 570 = -1315`

29 - [16+3.(51-40)= 29 - [16+3.11]

                          = 29 - [16+ 33]                       ( vi nhan chia truoc cong tru sau )

                          = 29 - 49

                          = - 20

chuc ban hoc tot

=29-[16+3.11]

=29-[16+33]

=29-49

= - 20

1: \(=-145\cdot13+145\cdot57+57\cdot10-57\cdot145=-1315\)

2: \(=17\cdot15-17\cdot16+16\cdot17-16\cdot20=255-320=-65\)

3: \(=-38\cdot25+38\cdot4-25\cdot4+25\cdot38=13\cdot4=52\)

4: \(=23\cdot145-23\cdot17-145\cdot23+145\cdot6=479\)

5: \(=24\cdot15-24\cdot4+4\cdot24-4\cdot15=360-60=300\)

6: \(=199\left(15-17+17-5\right)=199\cdot10=1990\)

7: \(=-39\cdot5+39\cdot99+99\cdot10-99\cdot39=795\)

bạn ơi viết rõ cách làm ra

= -5 - 37 - 45 + 51 + 37 - 51

= (-5 -45 )+ (37 - 37) + (51 - 51) 

= -50 

\(-5+\left(-37-45+51\right)-\left(-37+51\right)\)

\(=-5-37-45+51+37-51\)

\(=-\left(5+45\right)-\left(37-37\right)+\left(51-51\right)\)

\(=-50-0+0=-50\)

=-15+15+17-17-22+22

=0+17-17-22+22

=0+0-22+22

=0+0+0

=0

ngu v~