Bài 1: (3 điểm) Thực hiện các phép tính: a) (134-34).(-28)+72.[(-55)-45] b) 1+2-3-4+5+6-7-8+9+10-11-12+...+97+98-99-100 c) 2².4³ -625: {[504-(5².8+70):3² +6]:20+2023°}

Bài `1:`

`a)` `( 134 - 34 ) . ( -28 ) + 72 . [ ( -55 ) - 45 ]}`

`= 100 . ( -28 ) + 72 . ( -100 )`

`= 100 . ( -28 ) + ( -72 ) . 100`

`= 100 . [ ( -28 ) + ( -72 )`

`= 100 . ( -100 )`

`= -10 000 `

`b)` `1+2-3-4 + 5+6 -7-8 +10-11-12 + ...+97+98-99-100`

`= ( 1+2 - 3-4) +( 5+6 -7-8) + ....+(97+98 - 99-100)`

`= -4 + (-4) + ............+(-4)`

`= -4 . 25`

`= -100`

`c)` `2^2.4^3 -625: {[504-(5^2.8+70):3^2+6]:20+2023^0} `

`=4 . 64 - 625 : {[504-(25.8+70):9+6]:20+1} `

`=256 - 625 : {[504-(200+70):9+6]:20+1} `

`=256-625 : {[504-270+6]:20+1}`

`=256-625 : {[504-30+6]:20+1}`

`=256-625 : (480:20+1)`

`=256-625 : (24+1)`

`=256-625 : 25`

`=256-25`

`=231`