= 2k - (sqrt(k) + sqrt(m))(sqrt(k) - sqrt(m))= 2k - (k - m)= 2k - k + m= k + m
Therefore, the simplified expression is k + m.
= 2k - (sqrt(k) + sqrt(m))(sqrt(k) - sqrt(m))
= 2k - (k - m)
= 2k - k + m
= k + m
Therefore, the simplified expression is k + m.