【17.1-17.1÷（3.1-6/5）】x0.6
=(17.1-17.1÷1.9）×0.6
=（17.1-9）×0.6
=8.1×0.6
=4.86
0.28x4.17+0.28x5.83
=0.28×（4.17+5.83）
=0.28×10
=2.8