用简便方法计算39.98×26+19.99×74-199.9×2.6
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共2个回答
热心网友
39.98×26+19.99×74-199.9×2.6
=19.99×2×26+19.99×74-19.9.9×26
=19.99×(2×26+74-26)
=19.99×(26+74)
=19.99×100
=1999
热心网友
39.98×26+19.99×74-199.9×2.6
=399.8×2.6-199.9×2.6+19.99×74
=(399.8-199.9)×2.6+199.9×7.4
=199.9×2.6+199.9×7.4
=199.9×(2.6+7.4)
=199.9×10
=1999
