如题所述
1、【B】;
2、【4】;
3、598²=(600-2)²
=600²-2×600×2+2²
=360000-2400+4
=357604;
102²
=(100+2)²
=100²+2×2×100+2²
=10000+400+4
=10404;
89.8²
=(90-0.2)²
=90²-2×0.2×90+0.2²
=8100-36+0.04
=8064.04
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