14÷（1+30%-（1-2/5）=14÷(1.3-1+0.4)14÷0.7=20
=14÷(1.3-0.6)=14÷0.7=20
14/(1+0.3-0.6)=14/0.7=20
=14除以(1.3一0.6)=14除以0.7=20
