帮我做几道数学题(要简便运算)
33.3乘334+99.9乘22245.6乘6.7+4.56乘31+0.456乘20
15.8乘5.8+4.2乘4.2+11.6乘4.2
(0.05+0.05+0.05)乘9+0.05乘73