数学初一上册课时特训34页的答案1/1*3+1/3*5+1/5*7+……+1/2011*2013谁知道答案?
2019-04-21
数学初一上册课时特训34页的答案
1/1*3+1/3*5+1/5*7+……+1/2011*2013谁知道答案?
优质解答
1/1*3+1/3*5+1/5*7+……+1/2011*2013
=1/2(2/1*3+2/3*5+2/5*7+……+2/2011*2013)
=1/2(3-1)/1*3+(5-3)/3*5+(7-5)/5*7+……+(2013-2011)/2011*2013]
=1/2(1-1/3+1/3-1/5+1/5-1/7+……+1/2011-1/2013)
=1/2(1-1/2013)
=1/2*2012/2013
=1006/2013
1/1*3+1/3*5+1/5*7+……+1/2011*2013
=1/2(2/1*3+2/3*5+2/5*7+……+2/2011*2013)
=1/2(3-1)/1*3+(5-3)/3*5+(7-5)/5*7+……+(2013-2011)/2011*2013]
=1/2(1-1/3+1/3-1/5+1/5-1/7+……+1/2011-1/2013)
=1/2(1-1/2013)
=1/2*2012/2013
=1006/2013