3.9×1.4÷0.35
=3.9×(2*0.7)÷(0.5*0.7)
=3.9*(2÷0.5)
=3.9*4
=15.6
32.8×13.5÷4.5
=32.8×（4.5×3）÷4.5
=32.8×3
=98.4