А) 5/6 - 3/4 Б) 1/3 + 1/5

5/6-3/4=10/12-9/12=1/12 1/3+1/5=5/15+3/5=8/15

[latex] \frac{5}{6} - \frac{3}{4} = \frac{10-9}{12} = \frac{1}{12} [/latex] [latex] \frac{1}{3} + \frac{1}{5} = \frac{5+3}{15} = \frac{8}{15} [/latex]