4.25÷25×101-1.7 =0.17×101-1.7 =0.17×（100+1）-1.7 =0.17×100+0.17-1.7 =17+0.17-1.7 =15.47
4.25÷25×101-1.7=0.17*101-1.7=17+0.17-1.7=15.47
