So sanh A va B ma khong tinh cu the gia tri cua chung
a)2489 .2485
b)2487.2487
So sanh a va b ma khong tinh gia tri cu the cua chung:2136.2136 va2134.2138
2136*2136=2136*(2134+2)=2136*2134+2*2136=2136*2134+4272
2134*2138=2134*(2136+2)=2134*2136+2*2134=2134*2136+4268
Ta có: 4272>4268 nên 2134*2134+4272>2134*2136+4268 hay 2136*2136>2134*2138
Vậy 2136*2136>2134*2138
So sanh A va B ma khong tinh cu the gia tri cua chung :
A=2002.2002
(Goi y : a=(2002+2).2002)
B=2000.2004
B=2000.(2002+2)
A=2002.2002
A=(2000+2).2002
A=2000.2002+2002.2
B=2000.2004
B=2000.(2002+2)
B=2000.2002+2000.2
Vì 2000.2002=2000.2004; 2002.2>2000.2
=>2000.2002+2002.2> 2000.2004+2000.2
hay A>B
Vậy A>B
1.So sanh A va B ma khong tinh gia tri cu the cua chung:
a)A=2008.2008;B= 2006.2010
b)A= 47.36+53; B= 4835+90
2.Tich cua 4 so tu nhien lien tiep la 3024.Tim 4 so do.
Ai tra loi dung la hoc sinh uu tu
so sanh A va B ma khong can tinh gia tri cua A va B .
A=2004 . 2004
B = 2002 . 2006
\(a=2004.2004=2004.\left(2002+2\right)=2004.2002+2004.2\)
\(b=2002.2006=2002.\left(2004+2\right)=2002.2004+2002.2\)
Vì \(2004.2>2002.2\)
=>\(2004.2002+2004.2>2004.2+2002.2\)
=>\(a>b\)
\(A=\)\(2004.2004=2004.\left(2002+2\right)\)\(2004.2+2004.2002\)
\(B=2002.2006=2002.\left(2004+2\right)=2004.2+200.2\)
vì \(2004.2>2002.2\)
\(=>A>B\)
đ/s: \(A>B\)
khong tinh gia tri cu the, hay so sanh:
A= 98x76-25 va B= 73+ 98x75
A=98x76-25
= 98x(75+1)-25
=98x75+98-25
B=73+98x75
=98x75+73
=98x75+98-25
vi: 98x75+98-25 = 98x75+ 98-25
nen: A= 98x76-25 = 73+ 98x75
DO LA DAP AN CUA MINH
So sanh so A va B ma ko tinh gia tri cu the cua chung
a, A=2010×2010
B = 2009×2011
b, A=234234×233
B=233233×234
a . A = 2010 x 2010
B = 2009 x 2001
A= 2010 x 2010 = ( 2009 + 1 ) x 2010 = 2009 x 2010 + 2010
B = 2009 x 2011 = 2009 x ( 2010 + 1 ) x 2009 = 2010 x 2009 + 2009
Suy ra A > B
b . A = 234234 x 233
B = 233233 x 234
A = 234234 x 233 = 1001 x 234 x 233
A = 233233 x ( 233 + 1 ) = 233233 x 233 + 233 = 233 x 1001 x 233 + 233 = 233 x 1001 x 234
Vậy A = B
khong tinh gia tri cua a va b hay so sanh a va b va tinh hieu cua chung biet rang.
A=2004.2005
B=2000.2009
A = 2004.2005
= (2000 + 4).2005
= 2000.2005 + 4.2005
B = 2000.2009
= 2000.(2005 + 4)
= 2000.2005 + 2000.4
=> A > B
@Nguyễn Hoàng Nina
So sanh a va b ma khong tinh gia tri cua a va b
A=2016×2018 ; B = 2017× 2017
Ai lam đung minh se tich cho😙😙😙😙😙😙
Ta có :
\(A=2016.2018\)
\(\Rightarrow A=2016\left(2017+1\right)\)
\(\Rightarrow A=2016.2017+2016\)
Ta lại có :
\(B=2017.2017\)
\(\Rightarrow B=2017.\left(2016+1\right)\)
\(\Rightarrow B=2017.2016+2017\)
Ta thấy: \(2017>2016\)
\(\Rightarrow2017.2016+2017>2017.2016+2016\)
\(\Rightarrow B>A\)
So sanh giá trị của a va b ma ko can tinh gia tri cu the
a=300.300
b=299.300
a=300.300=(299+1).300=299.300+300
b=299.300
Vì 299.300 = 299.300
=> 299.300+300 > 299.300
Hay a > b
a=300.300
a=(299+1).300
a=299.300+300
b=299+300
b=(298+1).300
b=300.298+300