1998 x 502 + 1999 x 498
Giup tôi bài này nhe các bạn. Cảm ơn . 1998 x 502 + 1999 x 498
\(1998\cdot502+1999\cdot498\)
\(=1998\cdot502+1998\cdot498+1\cdot498\)
\(=1998\cdot\left(502+498\right)+498\)
\(=1998\cdot1000+498\)
\(=1998000+498\)
\(=1998498\)
Chúc bạn học tốt!!!
số cần tìm là:1998x502+1999x498=1998498
k mình nha
chúc bạn hok tốt
1998x502+1999x498
=1002996+995502
=1998498
NHO K CHO MINH NHE NEU CO BAI KHO TO NHAC CHO
KET BAN VOI MINH NHE
(1999 x 1998 + 1998 + 1997) x (1 + : 1
- 1
)
1999/2006 x 2006/2005 + (-1998)/1999 : 2005/1999
Tính nhanh:
( 1999 x 1998 + 1998 x 1997 ) x ( 1 + 1/2 : 1 1/2 - 1 1/3)
\(=\left(1999\times1998+1998\times1997\right)\times\left(1+\dfrac{1}{2}:1\dfrac{1}{2}-1\dfrac{1}{3}\right)\)
\(=\left(1999\times1998+1998\times1997\right)\times\left(1+\dfrac{1}{2}:\dfrac{3}{2}-\dfrac{4}{3}\right)\)
\(=\left(1999\times1998+1998\times1997\right)\times\left(1+\dfrac{1}{3}-\dfrac{4}{3}\right)\)
\(=\left(1999\times1998+1998\times1997\right)\times\left(\dfrac{4}{3}-\dfrac{4}{3}\right)\)
\(=\left(1999\times1998+1998\times1997\right)\times0\)
\(=0\)
1999 x 2011 - 1999
2010 x 1998 - 2010 =
1999 x 2011 - 1999
=1999 x 2011 -1999 x 1
=1999x(2011-1)
=1999 x 2010
= 4017990
2010 x 1998 - 2010
=2010 x 1998 -2010 x 1
= 2010 x ( 1998 -1 )
= 2010 x 1997
= 4013970
a)1999 x 2011 - 1999
= 4019989 - 1999
= 4017990
b)2010 x 1998 - 2010
= 4015980 - 2010
= 4013970
Mong bạn k mik
tinh bằng cách thuận tiện nhất:
1998 x 2000 - 1414/1999 x 1998 + 584
Là 1 e nhé!!!
1998 x 2000 - 1414 : 1999 x 1998 + 584
= (2000 - 1999) x (1414 +584) : 1998
= 1 x 1998 : 1998
= 1998 : 1998
= 1
Do lâu r cj chưa lm nên nếu có j thì e kiểm tra lại nhé <3
(1999 x 1998 + 1998 + 1997) x ( 1 + 1/2 : 1 1/2 - 1 1/3 )
(1999×1998+1998+1997)×(1/1+1/2:3/2-4/3)
(1999×1998+1998+1997)×(1/1+1/2×2/3-4/3)
1999×1998+1998+1997)×(1/1+1/3-4/3)
(1999×1998+1998+1997)×(4/3-4/3)
(1999×1998+1998+1997)×0
0
tính nhanh:
1999 x 2001 - 1/1998 + 1999 x 2000 x 7/5
Bài 1 : tính nhanh :
1999 x 2001 - 1 / 1998 + 1999 x 2000 x 7/5
Sửa lại :
\(=\frac{1999.2000+1999-1}{1998+1999.2000}.\frac{7}{5}=\frac{1999.2000+1998}{1998+1999.2000}.\frac{7}{5}=1.\frac{7}{5}=\frac{7}{5}\)
\(\frac{1999.2000-1}{1998+1999.2000}.\frac{7}{5}\)
= \(\frac{-1}{1998}\) . \(\frac{7}{5}\)
= \(\frac{-7}{9990}\)
\(\frac{1999.2000+1999}{1998+1999.2000}.\frac{7}{5}=1+\frac{1}{1998+1999.2000}.\frac{7}{5}=1+\frac{7}{5.\left(1998+1999.2000\right)}=1+\frac{7}{19999990}=\frac{19999997}{19999990}\)