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
1998 x 1996 + 1997 + 1995
--------------------------------------
1997 x 1996 - 1995 x 1996
Mình mới giải xong, mất tiêu bài rồi KQ=1000
1998 x 1996 + 1997 x 11 + 1985 : 1997 x 1996 - 1995 x 1996
1998 x 1996 + 1997 + 1995
---------------------------------------
1997 x 1996 - 1995 x 1996
help em bài này với
\(...=\dfrac{1998x1996+1996+1+1996-1}{\left(1997-1995\right)x1996}\)
\(=\dfrac{1998x1996+2x1996}{2x1996}=\dfrac{1996\left(1998+2\right)}{2x1996}=\dfrac{2000}{2}=1000\)
1998 x 1996 + 1997 x 11 + 1985/1997 x 1996 - 1995 x1996
so sánh bằng cách nhanh nhất
1996 x 1999 và 1997 x 1998
-1996x1999=1996x(1998+1)=1996x1998+1996
-1997x1998=(1996+1)x1998=1996x1998+1998
Vì vậy 1996x1999<1997x1998
mng giải giúp e với:
M=1991 x 1992 x 1993 x 1994 x 1995 x 1996 x 1997 x 1998 x 1999
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
Tìm x, biết x+1/1999+x+2/1998+x+3/1997=x+4/1996+x+4/1995+x+6/1994
Suy ra \(\frac{x+1}{1999}+1+\frac{x+2}{1998}+1=\frac{x+3}{1997}+1+\frac{x+4}{1996}\)
Suy ra \(\frac{x+2000}{1999}+\frac{x+2000}{1998}=\frac{x+2000}{1997}+\frac{x+2000}{1996}\)
Suy ra \(\frac{x+2000}{1999}+\frac{x+2000}{1998}-\frac{x+2000}{1997}-\frac{x+2000}{1996}=0\)
Suy ra \(x+2000.\left(\frac{1}{1999}+\frac{1}{1998}-\frac{1}{1997}-\frac{1}{1996}\right)=0\)
Vì \(\left(\frac{1}{1999}+\frac{1}{1998}-\frac{1}{1997}-\frac{1}{1996}\right)\ne0\)
Suy ra x+2000=0
Suy ra x=-2000
Hok tốt