计算: ①18.3×0.25+5.3÷0.4-7.13=_; ②1/20043−2003×(20042+2005)=_.
问题描述:
计算:
①18.3×0.25+5.3÷0.4-7.13=______;
②
=______. 1
20043−2003×(20042+2005)
答
①18.3×0.25+5.3÷0.4-7.13
=4.575+13.25-7.13
=17.825-7.13
=10.695;
②
1
20043−2003×(20042+2005)
=
1 20042×2004−2003×20042−2003×2005
=
1 20042×(2004−2003)−2003×2005
=
1 20042−2003×2005
=
1 20042−2003×(2004+1)
=
1 20042−2003×2004−2003
=
1 2004×(2004−2003)−2003
=
1 2004−2003
=1.
故答案为:10.695,1.