计算;F+f9C)w6Y;_9?
51.2 ×8.1 +11 ×9.25 +537 ×0.19;F+f9C)w6Y;_9?
算式：提示5f.}.a:t*n2O;F+f9C)w6Y;_9?
＝(T9L*?*i'S2{,?2\;F+f9C)w6Y;_9?