\(\frac{1996\times1997+1998\times3}{1997\times1999-1997\times1997}=?\)
\(\frac{-1}{2000\times1999}-\frac{1}{1999\times1998}-\frac{1}{1998\times1997}\)
\(\frac{-1}{2000\cdot1999}-\frac{1}{1999\cdot1998}-\frac{1}{1998\cdot1997}\)
\(=-\left(\frac{1}{2000\cdot1999}+\frac{1}{1999\cdot1998}+\frac{1}{1998\cdot1997}\right)\)
\(=-\left(\frac{1}{1997\cdot1998}+\frac{1}{1998\cdot1999}+\frac{1}{1999\cdot2000}\right)\)
\(=-\left(\frac{1}{1997}-\frac{1}{1998}+\frac{1}{1998}-\frac{1}{1999}+\frac{1}{1999}-\frac{1}{2000}\right)\)
\(=-\left(\frac{1}{1997}-\frac{1}{2000}\right)\)
\(=-\frac{3}{3994000}\)
giúp cái !!!!!!!!!!!!!!! : \(\frac{1997\times1996+1}{1995\times1997+1996}\)
CÓ LỜI GIẢI NỮA NHÉ
1997.1996+1=1997.(1995+1)+1=1997.1995+19971+1=1997.1995+1998
\(\frac{1997x1996+1}{1995x1997+1996}\)=\(\frac{1996+1}{1995+1996}\)=\(\frac{1}{1995}\)
So sánh bt A=1996/1997+1997/1998 với B=1996+1997/1997+1998
tính nhanh
\(\frac{1995\times1997-1}{1996\times1995+199}\)
1995(1996+1)-1/1996.1995+1994
1995.1996+1995-1/1996.1995+1994
1995.1996+1994/1996.1995+1994=1
\(\frac{1995.1997-1}{1996.1995+199}\)= \(\frac{1995.\left(1996+1\right)-1}{1996.1995+199}\)
= \(\frac{1995.1996+1995.1-1}{1996.1995+199}\)
= \(\frac{1995.1996+1994}{1996.1995+199}\)
làm đến đây thì mình chịu
sai đề rồi bạn ơi phải là 1995*1997-1
1996*1995+1994
1998 x 1996 + 1997 + 1995
--------------------------------------
1997 x 1996 - 1995 x 1996
Mình mới giải xong, mất tiêu bài rồi KQ=1000
1998×1996+1997×11+1985
1997×1996-1995×1996=?
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
1998 x 1996 + 1997 x 11 + 1985 : 1997 x 1996 - 1995 x 1996
Tính nhanh :
( 1996 * 1997 + 1998 * 3 ) : ( 1997 * 1999 - 1997 * 1997 )
( 1996 * 1997 + 1998 * 3 ) : ( 1997 * 1999 - 1997 * 1997 ) = 999,500751