1又3/25+[(1.5+2又2/3)÷3又3/4-0.4]÷8又8/9
=28/25+[(3/2+8/3)÷15/4-0.4]÷80/9
=28/25+[(3/2+8/3)×4/15-0.4]×9/80
=28/25+[(2/5+32/45-2/5]×9/80
=28/25+[32/45]×9/80
=28/25+2/25
=30/25
=6/5
=1.2
1又3/25+[(1.5+2又2/3)÷3又3/4-0.4]÷8又8/9
=28/25+[(3/2+8/3)÷15/4-0.4]÷80/9
=28/25+[(3/2+8/3)×4/15-0.4]×9/80
=28/25+[(2/5+32/45-2/5]×9/80
=28/25+[32/45]×9/80
=28/25+2/25
=30/25
=6/5
=1.2