(1)2.64×1.7-2.64×0.7=2.64×(1.7-0.7)=2.64×1=2.64(2)31.5×1.07-3.15×0.7=3.15×10.7-3.15×0.7=3.15×(型庆凯10.7-0.7)=3.15×10=31.5(3)2.7×5.7-2.7+5.3×2.7=2.7×(5.7-1+5.3)=2.7×10=27(4)0.625÷0.125×0.8=(0.625×0.8)×8÷(0.128×8)=0.5×8÷1=4(5)18.6×6.1+3.9×18.6=18.6×(6.1+3.9)卜唤=18.6×10=186(6)1.3579+3.5791+5.7913+7.9135+9.1357=(1+3+5+7+9)×1.1111=25×1.1111=27.7775(7)52.5x2.9+5.45=5.25x29+5.25+0.2=5.25×(差扒29+1)+0.2=5.25×30+0.2=157.5+0.3=157.7(8)0.92x15+0.08x15=(0.92+0.08)×15=1×15=15(9)0.72×1.25×2.5=0.9×(0.8×1.25)×2.5=0.9×1×2.5=2.25(10)400.6x7-2003x0.4=200.3x14-200.3x4=200.3×(14-4)=200.3×10=2003
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