1. 199.7+997.7+977.1-1997.71 2. 7.2 乘以61.3加73.8乘以2.8
1. 199.7+997.7+977.1-1997.71
=200-0.3+1000-2.3+1000-22.9-2000+2.29
=200-2.6-22.9+2.29
=200-22.9-0.41
=200-22-1.31
=178-1.31
=176.69
2. 7.2 ×61.3 + 73.8×2.8
=7×61.3+0.2×61.3+73.8×(3-0.2)
=429.1+12.26+221.4-14.76
=429.1+221.4+12.26-14.76
=650.5-2.5
=648
=200-0.3+1000-2.3+1000-22.9-2000+2.29
=200-2.6-22.9+2.29
=200-22.9-0.41
=200-22-1.31
=178-1.31
=176.69
2. 7.2 ×61.3 + 73.8×2.8
=7×61.3+0.2×61.3+73.8×(3-0.2)
=429.1+12.26+221.4-14.76
=429.1+221.4+12.26-14.76
=650.5-2.5
=648
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第1个回答 2011-11-28
7.2 ×61.3 + 73.8×2.8
=7×61.3+0.2×61.3+73.8×(3-0.2)
=429.1+12.26+221.4-14.76
=429.1+221.4+12.26-14.76
=650.5-2.5
=648
=7×61.3+0.2×61.3+73.8×(3-0.2)
=429.1+12.26+221.4-14.76
=429.1+221.4+12.26-14.76
=650.5-2.5
=648
第2个回答 2020-05-20
