Question

15/21×3/4+10/21÷4/3-3/4 用简便计算

Answer 1

=15/21×3/4+10/21×3/4-3/4
=(15/21+10/21-1)×3/4
=4/21×3/4
=1/7

Answer 2

15/21×3/4+10/21÷4/3-3/4
=15/21×3/4+10/21×3/4-3/4
=3/4×(15/21+10/21-1)
=3/4×4/21
=1/7

追问

18/19×17