Question

 

 

tính nhanh

\(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)

 

 

 

Answer 1

\(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)

\(=\frac{1999}{2011}-\frac{2011}{1999}-\frac{12}{1999}+\frac{12}{2011}\)

\(=(\frac{1999}{2011}+\frac{12}{2011})-(\frac{2011}{1999}-\frac{12}{1999})\)

\(=1-1=0\)

Answer 2

\(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)

\(=\frac{1999}{2011}-\frac{2011}{1999}+\frac{12}{1999}+\frac{12}{2011}\)

\(=\left(\frac{1999}{2011}+\frac{12}{2011}\right)+\left(\frac{-2011}{1999}+\frac{12}{1999}\right)\)

\(=1-1\)

\(=0\)

Linz