把2012放里边.
就= 2012x[ 2013/ 2012(2013+1)]
=2013/2014不太明白，能否讲详细点？谢谢！2012÷2012又2012/2013= 2012 ÷(2012 + 2012/2013) =2012 ÷(2012x2013 + 2012)/2013= (2012x 2013)/(2012x2013 + 2012)= (2012x 2013)/(2013 + 1)2012= 2013 /2014= (2012x 2013)/(2012x2013 + 2012)= (2012x 2013)/(2013 + 1)2012= 2013 /2014 这部分还不太懂，劳驾帮忙。谢谢！= (2012x 2013)/(2012x2013 + 2012)= (2012x 2013)/(2012x2013 + 2012x1)= (2012x 2013)/[2012 x (2013 + 1)]= (2012x 2013)/(2012 x 2014)= 2013 /2014