Tính nhanh 2/3 : 5/7 x 5/7 : 2/3 + 2019

2 bình luận về “Tính nhanh 2/3 : 5/7 x 5/7 : 2/3 + 2019”

1. Tính nhanh: 2/3 : 5/7 xx 5/7 : 2/3 + 2019

   2/3 : 5/7 xx 5/7 : 2/3 + 2019

   = 2/3 : 2/3 xx 5/7 : 5/7 + 2019

   = 1 xx 1 + 2019

   = 1 + 2019

   = 2020

   Trả lời
2. Ta có:2/3: 5/7. 5/7: 2/3+2019

        = 2/3. 7/5. 5/7. 3/2+2019

       =2/3. 3/2. 5/7. 7/5+2019

       =1+2019

      =2020

   Trả lời