bài 2 tính nhanh a 26×7-17×9+13×26-17×11 b 1167:6+33:6 c 1754:17-74:17+20:17

`text{Đáp án}`

`a)=180`

`b)=200`

`c)=100`

`text{Giải thích các bước giải:}`

`a)` 
`26.7-17.9+13.26-17.11`
`=26.7+13.26-17.9-17.11`

`=[26.7+13.26]-[17.9+17.11]`
`=[26.(7+13)]-[17.(9+11)]`
`=26.20-17.20`
`=20.(26-17)`
`=20.9`
`=180`
`b)`
`1167:6+33:6`
`=(1167+33):6`
`=1200:6`
`=200`
`c)`
`1754:17-74:17+20:17`
`=(1754-74+20):17`
`=1700:17`
`=100`