51*49+3.51*49+3.51*51=?
51*49+3.51*49+3.51*51
=51×49+3.51×(49+51)
=51×49+3.51×100
=51×49+351
=51×49+51+300
=51×50+50×6
=50×57
=2850
=51×49+3.51×(49+51)
=51×49+3.51×100
=51×49+351
=51×49+51+300
=51×50+50×6
=50×57
=2850
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第1个回答 2009-06-29
原式=51*49+3.51*100=50*49+49+351=490+400=890
第2个回答 2009-06-29
51*49+3.51*49+3.51*51
=(50-1)(50+1)+3.51(49+51)
=2500-1+351
=2500+350
=2850
=(50-1)(50+1)+3.51(49+51)
=2500-1+351
=2500+350
=2850