原式等于0.4×（8.2+0.8+1）=4回答完毕~有疑问请追问~无疑问请点击【采纳】~祝学习进步\(^o^)/~~~
0.4×8.2+0.4×0.8+0.4=0.4x（8.2+0.8+1）=0.4x（9+1）=0.4x10=4谢谢，请采纳
0.4*[8.2+0.8+1]=0.4*10=4
0.4*（8.2+0.8+1）=4
