12.3-(4.74+1.49+2.3)=12.3-2.3-（4.74+1.49）=10-4.74-1.49=5.26-2+0.51=3.26+0.51=3.77
12.3-(4.74+1.49+2.3)=12.3-2.3-（4.74+1.49）=10-6.23=3.77
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自己算☺️😉😚😅
