99.8×(-100.2) 简便计算.平方差公式
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99.8×(-100.2) 简便计算.平方差公式
![99.8×(-100.2) 简便计算.平方差公式](/uploads/image/z/15590609-17-9.jpg?t=99.8%C3%97%EF%BC%88-100.2%EF%BC%89+%E7%AE%80%E4%BE%BF%E8%AE%A1%E7%AE%97.%E5%B9%B3%E6%96%B9%E5%B7%AE%E5%85%AC%E5%BC%8F)
99.8×(-100.2)
=(100-0.2)(-100-0.2)
=-(100-0.2)(100+0.2)
=-(100²-0.2²)
=-(10000-0.04)
=-9999.96
=(100-0.2)(-100-0.2)
=-(100-0.2)(100+0.2)
=-(100²-0.2²)
=-(10000-0.04)
=-9999.96