Question

Tính nhanh:

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

Answer 1

\(\left(\frac{1999}{2011}-\frac{2011}{199}\right)-\left(-\frac{12}{1999}-\frac{12}{2001}\right)\)

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

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

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

=1+1

=2

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

=-2

Answer 3

=-2