19.94x2010-19.93x2011
=(19.93+0.01)×2010-19.93×(2010+1)
=19.93x2010+0.01×2010-19.93×2010-19.93
=0.01×2010-19.93
=20.1-19.93
=0.17
19.94x2010-19.93x2011
= 19.94x2010-19.93x(2010+1)
= 19.94x2010-19.93x2010 - 19.93×1
= (19.94-19.93)x2010 - 19.93
= 0.01×2010-19.93
= 20.10-19.93
= 0.17
19.94×2010-19.93×2011
=(19.93+0.01)×2010-19.93×(2010+1)
=19.93×2010+0.01×2010-19.93×2010-1
=0.01×2010-19.93
=20.1×19.93
=0.17