Question

\(\frac{2011+2012}{2012+2013}va\frac{2011}{2012}+\frac{2012}{2013}\)

 so sanh va ghi loi giai day du nha

Answer 1

đặt \(A=\frac{2011+2012}{2012+2013};B=\frac{2011}{2012}+\frac{2012}{2013}\)

ta có:\(A=\frac{2011+2012}{2012+2013}=\frac{2011}{2012+2013}+\frac{2012}{2012+2013}\)

\(\frac{2011}{2012+2013}<\frac{2011}{2012};\frac{2012}{2012+2013}<\frac{2012}{2013}\)

=>A<B

 

Answer 2

\(\frac{2011+2012}{2012+2013}=\frac{2011}{2012+2013}+\frac{2012}{2012+2013}\)

rồi bây giờ thấy ngay đáp án r tự làm đi

Answer 3

Ta có: \(\frac{2011}{2012}>\frac{2011}{2013+2012};\frac{2012}{2013}>\frac{2012}{2012+2013}\)

=>\(\frac{2011}{2012}+\frac{2012}{2013}>\frac{2011}{2012+2013}+\frac{2012}{2012+2013}=\frac{2011+2012}{2012+2013}\)

Vậy\(\frac{2011}{2012}+\frac{2012}{2013}>\frac{2011+2012}{2012+2013}\)

k cho mk nha