Tính nhanh :
( 1996 * 1997 + 1998 * 3 ) : ( 1997 * 1999 - 1997 * 1997 )
tính nhanh : 1996*1997+1998*3+1994/1997*1999-1997*1997
1996 x 1997 + 1998 x 3 + 1994 / 1997 x 1999 - 1997 x 1997
= 1996 x 1997 + ( 1997 + 1 x 3 ) + 1994 / 1997 x 1999 - 1997 x 1997
= 1996 x 1998 + 1 x 3 + 1994 / 1997 x 1999 - 1997 x 1997
= 3988008 + 3 + 1994 / 1997 x 1999 - 1997 x 1997
= 3990005 / 1997 x 1999 - 1997 x 1997
= 3990005 / ( 1999 - 1997 ) x 1997
= 3990005 / 3994
đáp án bằng : 1,109629008840861 nha bạn mk nha
1996*1997+1998*3+1994/1997*1999-1997*1997 tinh nhanh
1996*1997+1998*3+1994 trên 1997*1999-1997*1997
\(\frac{1996\times1997+1998\times3+1994}{1997\times1999-1997\times1997}\)
= \(\frac{1996\times1997+\left(1997+1\times3\right)+1994}{1997\times1999-1997\times1997}\)
= \(\frac{1996\times1998+1\times3+1994}{1997\times1999-1997\times1997}\)
= \(\frac{3990005}{1997\times1999-1997\times1997}\)
= \(\frac{3990005}{\left(1999-1997\right)\times1997}\)
= \(\frac{3990005}{3994}\)
1996 x 1997 + 1998 x 3
1997 x 1999 + 1997 x 1997
1996 x 1997 + 1998 x 3 + 1994 / 1997 x 1999 - 1997 x 1997
Tính nhanh biểu thức sau:
A= 1998*1996+1997*11+1985/1997*1996-1995*1996
Tính nhanh
\(\dfrac{1996\cdot1997+1998\cdot3+1994}{1997\cdot1999-1997\cdot1997}\)
\(\dfrac{1996\cdot1997+\left(1997+1\right)\cdot3+1994}{1997\cdot\left(1999-1997\right)}\) = \(\dfrac{1996\cdot1997+3\cdot1997+1997}{1997\cdot2}\)
\(\dfrac{1997\cdot\left(1996+3+1\right)}{1997\cdot2}\) = \(\dfrac{2000}{2}\)= \(1000\)
Tính nhanh :
1998 . 1996 + 1997 . 11 + 1985
----------------------------------------------
1997 .1996 - 1995 . 1996
Ta có : ( 1998 * 1996 + 1997 * 11 + 1985 ) / ( 1997 * 1996 - 1995 * 1996 ) .
= ( 1998 * 1997 - 1998 + 1997 * 11 + 1985 ) / 1996 * ( 1997 - 1995 ) .
= [ 1997 * ( 1998 + 11 ) - 1998 + 1985 ] / 1996 * 2 .
= [ 1997 * 2009 - 13 ] / 1996 * 2 .
= [ 1996 * 2009 + 2009 - 13 ] / 1996 * 2 .
= [ 1996 * 2009 + 1996 ] / 1996 * 2 .
= [ 1996 * ( 2009 + 1 ) / 1996 * 2 .
= 1996 * 2010 / 1996 * 2 .
= 1005 .
So sánh bt A=1996/1997+1997/1998 với B=1996+1997/1997+1998