Вычислите а)2 3/14 - 19/4 б) 17/12 - 2/3

[latex]2 \frac{3}{14} - \frac{19}{4} =2 \frac{6}{28} - \frac{133}{28} = 2 \frac{6}{28} - 4 \frac{21}{28} = -2 \frac{15}{28} [/latex] [latex] \frac{9}{12} - \frac{2}{3} = \frac{9}{12} - \frac{8}{12} = \frac{1}{12} [/latex] [latex] \frac{17}{12} - \frac{2}{3} = \frac{17}{12} - \frac{8}{12} = \frac{9}{12} = \frac{3}{4} [/latex]