1.225+2.225+3.225+.+50.225等于多少?我等着用呢,最好把规律说出来,以后我就会做了还有一道题:(2008-1)+(2007-2)+(2006-3)+......(1005-1004)也要告诉我规律和答案
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1.225+2.225+3.225+.+50.225等于多少?我等着用呢,最好把规律说出来,以后我就会做了还有一道题:(2008-1)+(2007-2)+(2006-3)+......(1005-1004)也要告诉我规律和答案
1.225+2.225+3.225+.+50.225等于多少?
我等着用呢,最好把规律说出来,以后我就会做了
还有一道题:(2008-1)+(2007-2)+(2006-3)+......(1005-1004)也要告诉我规律和答案
1.225+2.225+3.225+.+50.225等于多少?我等着用呢,最好把规律说出来,以后我就会做了还有一道题:(2008-1)+(2007-2)+(2006-3)+......(1005-1004)也要告诉我规律和答案
原式=1+2+3.+50+0.225*50
1+0.225=1.225 2+0.225=2.225
同理,把每项拆开
=(1+50)*50/2 +11.25
将整数和小数分别组合,整数利用等差数列求解,小数是50个0.225的和,即0.225*50
=1286.25
1.225+2.225+3.225+......+50.225
=0.225×50+(1+50)×50/2
=11.25+1275
=1286.25
1.225+2.225+3.225+......+50.225
=1+2+3+...+50+0.225*50
=(1+50)*50/2+11.25
=51*25+11.25
=1275+11.25
=1286.25
(2008-1)+(2007-2)+(2006-3)+......(1005-1004)
=2007+2005+2003+20...
全部展开
1.225+2.225+3.225+......+50.225
=1+2+3+...+50+0.225*50
=(1+50)*50/2+11.25
=51*25+11.25
=1275+11.25
=1286.25
(2008-1)+(2007-2)+(2006-3)+......(1005-1004)
=2007+2005+2003+2001+1999+...+9+7+5+3+1
=(2007+1)+(2005+3)+(2003+5)+ ...
=2008+2008+2008+...
=(2008/2)*(((2007-1)/2)+1)
=1004*1004
=1008016
收起
跟 1加到100是一样的嘛。首尾相加~乘以25
(1+2+3+...+50)+0.225*50
=1286.25
=1+2+3+4+。。。+50+0.225*50
=(1+50)*50/2+11.25
=1275+11.25
=1286.25
1286.25
整数部分是1+2+3+……+50=(1+50)*50/2=1275
小数部分是0.225*50=11.25
整数部分和小数部分加起来1286.25
1+2+....+50+0.2*50+0.02*50+0.005*50=1275+10+1+0.25=1286.25
希望能帮到你