10) 6,9 + \(\left\)\(-4\frac{7}{9}\right\) =

\(6.9=\frac{69}{10}\), \(-4\frac{7}{9}=-\frac{43}{9}\).

\(\frac{69}{10}-\frac{43}{9}=\frac{621-430}{90}=\frac{191}{90}=2\frac{11}{90}\).

Ответ: \(2\frac{11}{90}\).