13⼀49×21+13×28⼀49简便算法

2025-06-25 09:46:43
推荐回答(4个)
回答1:

13/49×21+13×28/49
=13/49 ×(21+28)
=13/49 ×49
=13

回答2:

13/49*21+13*28/49
=13*(21/49+28/49)
=13

回答3:

13/49×21+13×28/49
=13/49*(21+28)
=13/49*49
=13

回答4:

13/49×21+13×28/49=13/7*3+13*4/7=13/7*(3+4)=13