Tính nhanh: (1995 . 19996 - 1997) / (1995.1994 + 1993)
Tính nhanh: \[\frac{{1995{\rm{ }}.{\rm{ }}1996{\rm{ }}--1997}}{{1995\,\,.\,\,1994\,\, + \,\,1993}}\].
\[\frac{{1995{\rm{ }}.{\rm{ }}1996{\rm{ }}--1997}}{{1995\,\,.\,\,1994\,\, + \,\,1993}}\]
\[ = \frac{{1995{\rm{ }}.{\rm{ }}\left( {1995 + 1} \right){\rm{ }}--1997}}{{1995\,\,.\,\,\left( {1995 - 1} \right)\,\, + \,\,1993}}\]
\[ = \frac{{1995.1995 + 1995 - 1997}}{{1995.1995 - 1995 + 1993}}\]
\[ = \frac{{1995.1995 - 2}}{{1995.1995 - 2}}\]
= 1