Đáp án `` Giải thích các bước giải`:`

Bài `3:`

`a) 135*3^2-4^2:130`

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

`= 5*9`

`=45v

`b) (2^3*9^4+9^3*45):(9^2*10-9^2)`

`= (8*9^4+9^3*9*5):[9^2*(10-1)]`

`= (8*9^4+9^4*5):(9^2*9)

`= (8+5)*9^4:9^3

`= 13*(9^4:9^3)`

`= 13*9`

`= 117`

`c) (20*2^4+12*2^4-48*2^2):8^2`

`= (5*2^2*2^4+3*2^2*2^4-3*2^4*2^2):(2^3)^2`

`= (5*2^6+3*2^6-3*2^6):2^6`

`= (5+3-3)*2^6:2^6`

`= 5*1`

`=5`

`d) 98*42-50[(18-2^3):2+3^2]`

`= 98*42-50[(18-8):2+3^2]`

`= 98*42-50(10:2+3^2)`

`= 98*42-50(5+9)`

`= 98*3*14-50*14`

`=(294-50)*14`

`= 244*14`

`= 3416`

Bài `4:`

`a) [461+(-78)+40]+(-461)`

`= 461-78+40-461`

`= (461-461)+[(-78)+40]`

`= 0+(-38)`

`= -38`

`b) [53+(-76)]-[(-76)-(-53)]`

`= 53+(-76)+76-53`

`= (53-53)+[(-76)+76]`

`=0+0`

`=0`

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