Trang chủ » Hỏi đáp » Môn Toán Tính nhanh : `c)` `3/7` . `9/26` `-` `1/14` . `1/3` `-` `1/7` `d)` `-5/13` . `5/9` . `(13/-5)` . `-18` 18/11/2023 Tính nhanh : `c)` `3/7` . `9/26` `-` `1/14` . `1/3` `-` `1/7` `d)` `-5/13` . `5/9` . `(13/-5)` . `-18`
Trả lời : ↓ c) 3/7×9/26-1/14×1/3-1/7 =27/182-1/14×1/3-1/7 =27/182-1/42-1/7 =1134/7644-182/7644-1/7 =34/273-1/7 =34/273-39/273 =-5/273 d) -5/13×5/9×(13/-5)×(-18) =-5/13×5/9×(-13/5)×(-18) =-25/117×(-13/5)×(-18) =5/9×(-18) =-10 Trả lời