[tex]21kg-8\frac{3}{5}kg-6\frac{4}{5}kg=\frac{105}{5}kg-\frac{43}{5}kg-\frac{34}{5}kg=\frac{28}{5}kg=5\frac{3}{5}kg[/tex]
Odp.[tex]5\frac35kg[/tex]
