[Toán 9] SO SÁNH

N

nhochehe2000

Last edited by a moderator:
B

baochauhn1999

Ta có:
(2010−2009)(2010+2009)=2010−2009=1(\sqrt{2010}-\sqrt{2009})(\sqrt{2010}+\sqrt{2009})=2010-2009=1
(2009−2008)(2009+2008)=2009−2008=1(\sqrt{2009}-\sqrt{2008})(\sqrt{2009}+\sqrt{2008})=2009-2008=1
=>(2010−2009)(2010+2009)=(2009−2008)(2009+2008)=>(\sqrt{2010}-\sqrt{2009})(\sqrt{2010}+\sqrt{2009})=(\sqrt{2009}-\sqrt{2008})(\sqrt{2009}+\sqrt{2008})
Mà:
2010+2009\sqrt{2010}+\sqrt{2009}>2009+2008\sqrt{2009}+\sqrt{2008}
Nên:
2010−2009\sqrt{2010}-\sqrt{2009}<2009−2008\sqrt{2009}-\sqrt{2008}
 
You must log in or register to reply here.
Top Bottom