计算下面各题，能简算的要简算．0.89×100.172×0.82+2.8×8.21.3×5.8+4.2（45.9-32.7）÷8÷0.125．

Question

计算下面各题，能简算的要简算．
0.89×100.1
72×0.82+2.8×8.2
1.3×5.8+4.2
（45.9-32.7）÷8÷0.125．

Answer 1

（1）0.89×100.1
=0.89×（100+0.1）
=0.89×100+0.89×0.1
=89+0.089
=89.089

（2）72×0.82+2.8×8.2
=7.2×8.2+2.8×8.2
=8.2×（7.2+2.8）
=8.2×10
=82

（3）1.3×5.8+4.2
=7.54+4.2
=11.74

（4）（45.9-32.7）÷8÷0.125
=13.2÷（8×0.125）
=13.2÷1
=13.2