能简算要简算、谢谢能简算要简算、谢谢
能简算要简算、谢谢
=7/4+[31/14-31/14+15/8]×12/25
=7/4+15/8×12/25
=7/4+9/10
=35/20+18/20
=43/20
=2又3/20.