怎样简便怎样算.我要式子.（8.6—5.8）×2. - 知识问答

怎样简便怎样算.我要式子.（8.6—5.8）×2.4—0.8928×0.25×6

2个回答

（8.6—5.8）×2.4—0.89
=2.8×2.4-0.89
=(2.6+0.2)(2.6-0.2)-0.89
=2.6²-0.04-0.89
=6.76-0.93
=6.76-1+0.07
=5.76+0.07
=5.83
28×0.25×6
=7×4×0.25×6
=7×1×6
=42

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