解4.28-5.2÷0.8×0.6
=4.28-5.2÷(4/5)×0.6
=4.28-5.2×(5/4)×0.6
=4.28-5.2×(1/4)×5×0.6
=4.28-1.3×3
=4.28-3.9
=0.38