问题
解答题
简便运算. (
23
200.9×10%+2.009×490+0.2009×5000. |
答案
①(
+2 71
)×23+1 69
,25 71
=
×23+2 71
×23+1 69
,25 71
=(
+46 71
)+25 71
,23 69
=1+
,1 3
=1
;1 3
②
×100+100×5 8
,3 8
=100×(
+5 8
),3 8
=100×1,
=100;
③23
×32 3
+1 2
+1 6
+1 12
+1 20
,1 30
=
×71 3
+7 2
-1 2
+…+1 3
-1 5
,1 6
=
+497 6
-1 2
,1 6
=
+497 6
,2 6
=
,499 6
=83
;1 6
④200.9×10%+2.009×490+0.2009×5000,
=20.09×1+20.09×49+20.09×50,
=20.09×(1+49+50),
=20.09×100,
=2009.