(1)(42×
6
7 -20)÷4
=(36-20)÷4
=16÷4
=4;
(2)(1
3
5 ×2+0.4)÷25%
=(3.2+0.4)÷0.25
=3.6÷0.25
=14.4.
答:(1)商是4,(2)这个数是14.4.