[tex]3 \frac{1}{7} + 5 \frac{4}{7} - 1 \frac{6}{7} = 8 \frac{5}{7} - 1 \frac{6}{7} = 7 \frac{12}{7} - 1 \frac{6}{7} = 6 \frac{6}{7} [/tex]
[tex]4 - (5 \frac{1}{3} - 2 \frac{2}{3}) = 4 - 5 \frac{1}{3} + 2 \frac{2}{3} = 3 \frac{3}{3} - 5 \frac{1}{3} + 2 \frac{2}{3} = - 2 \frac{2}{3} + 2 \frac{2}{3} = 0[/tex]
