2012又2010分之1乘2011分之2010
=2012x2010/2011+1/2010x2010/2011
=(1+2011)x2010/2011+1/2011
=2010/2011+2010+1/2011
=2010+(1/2011+2010/2011)
=2011
2012又2010分之1乘2011分之2010
=(2011+2011/2010)x2010/2011
=2011x2010/2011+2011/2010x2010/2011
=2010+1
=2011
2012又1/2010×2010/2011
=(2011+1又1/2010)×2010/2011
=2011×2010/2011+1又1/2010×2010/2011
=2010+2011/2010×2010/2011
=2010+1
=2011