So sánh 2 phân số \(\frac{2010}{2009}\)và\(\frac{2009}{2010}\)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(B=\frac{2009^{2010}-2}{2009^{2011}-2}< 1\)
\(\Rightarrow B=\frac{2009^{2010}-2}{2009^{2011}-2}< \frac{2009^{2010}-2+2011}{2009^{2011}-2+2011}=\frac{2009^{2010}+2009}{2009^{2011}+2009}\)\(=\frac{2009.\left(2009^{2009}+1\right)}{2009.\left(2009^{2010}+1\right)}=\frac{2009^{2009}+1}{2009^{2010}+1}\)
Suy ra : \(\frac{2009^{2010}-2}{2009^{2011}-2}< \frac{2009^{2009}+1}{2009^{2010}+1}\) hay \(B< A\)
Vậy \(A>B\)
\(B=\frac{2008+2009+2010}{2009+2010+2011}\)
\(=\frac{2008}{2009+2010+2011}+\frac{2009}{2009+2010+2011}+\frac{2010}{2009+2010+2011}\)
\(< \frac{2008}{2009}+\frac{2009}{2010}+\frac{2010}{2011}=A\)
do \(2009^{2009}-2< 2009^{2010}-2\Rightarrow B< 1\)
theo bài ra ta có:
\(B=\frac{2009^{2010}-2}{2009^{2011}-2}< \frac{2009^{2010}-2+2011}{2009^{2011}-2+2011}=\frac{2009^{2010}+2009}{2009^{2011}+2009}=\frac{2009\left(1+2009^{2009}\right)}{2009\left(1+2009^{2010}\right)}\)
\(=\frac{2009^{2009}+1}{2009^{2010}+1}=A\Rightarrow B< A\)
chúc bạn học tốt!!!
Ta có B có tử và mẫu bằng nhau=> B = 1
Vi 20092009<20092010=>20092009+1<20092010+1
Vậy A có từ< mẫu=>A<1
=>A<B
VẬy A<B
Kết bạn với mình nhé
2009A=2009^2010+2009/2009^2010+1 2009B=2009^2011-4018/2009^2011-2
2009A=1 + 2009/2009^2010+1 B=1 - 4016/2009^2011-2
mình viết tách ra cho khỏi nhầm
vì A>1 và B<1
nên A>B
VẬY A>B AND kết bạn nha
A=2009^2009+1/2009^2010+1 B=2009^2010-2/2009^2011-2
A=(2009^2009+1).10/2009^2010+1 B=(2009^2010-2).10/2009^2011-2
A=2009^2010+10/2009^2010+1 B= 2009^2011-20/2009^2010-2
A=(2009^2010+1)+9/2009^2010+1 B=(2009^2011-2)-18/2009^2010-2
A=1 + 9/2009^2010+1 B=1+(-18/2009^2010-2)
Vì 9/2009^2010+1 > (-18/2009^2010-2)
=>1 + 9/2009^2010+1>1+(-18/2009^2010-2)
Hay 2009^2009+1/2009^2010+1 > 2009^2010-2/2009^2011-2
Vậy A>B
B = 2009^2010 - 2 / 2009^2011 - 2 < 2009^2010 - 2 + 2011 /2009^2011 - 2 + 2011
= 2009^2010 + 2009 / 2009^2011 + 2009
= 2009 ( 2009^2009 + 1) / 2009(2009^2010 + 1)
= 2009^2009 + 1 / 2009^2010 + 1 = A
=> B < A
B=20092010-2/20092011-2<20092010-2+2011/20092011-2+2011=20092010+2009/20092011+2009 =2009.(20092009+1)/2009.(20092010+1)=20092009+1/20092010+1
Suy ra A>B
Đặt A = \(\frac{2009^{2009}+1}{2009^{2010}+1}\)
B = \(\frac{2009^{2010}-2}{2009^{2011}-2}\)
Do 20092010- 2 < 20092011- 2 => \(B<1\)
\(B=\frac{2009^{2010}-2}{2009^{2011}-2}<\frac{2009^{2010}-2+2011}{2009^{2011}-2+2011}=\frac{2009^{2010}+2009}{2009^{2011}+2009}=\frac{2009\left(1+2009^{2009}\right)}{2009\left(1+2009^{2010}\right)}\)
\(=\frac{2009^{2009}+1}{2009^{2010}+1}=A\Rightarrow\)B < A
\(\frac{2010}{2009}>1,\frac{2009}{2010}< 1\)
nên\(\frac{2010}{2009}>\frac{2009}{2010}\)