0.75╳50╳0.4=0.75╳(50╳0.4)=0.75x20=15希望能帮到你,请采纳正确答案,点击【采纳答案】,谢谢 ^_^你的点赞或采纳是我继续帮助其他人的动力
0.75x50x0.4=0.75x(50x0.4)=0.75x20=15
0.75×50×0.4=0.75×(50×0.4)=0.75×20=15