Question

5/9乘10减5/9简便计算

Answer 1

9分之5×10-9分之5
=9分之5×(10-1)
=9分之5×9
=5

Answer 2

（10-1）*5/9=5

追问

28/27乘19减19/27简便计算

追答

19+19/27-19/27=19
注：(28/27)*19=(1+(1/27))*19=19+19/27