0.45x102=（100+2）x0.45=100x0.45+2x0.45=45+0.9=45.9
链山闹棚罩唯陵
0.45×102=0.45×(1.02-0.02)=0.45×100+0.45×2=450+0.9=450.9
102乘以0.45+2乘以0.45等于45+0.9等于45.9
瞎渗族磨弊喊羡
