A)4 целых 11/15+2целых 7/20; б)5целых 2/7-4целых11/14

[latex]4 \frac{11}{15} +2 \frac{7}{20} = \frac{71}{15} + \frac{47}{20}= \frac{284+141}{60} = \frac{425}{60}= 7\frac{5}{60} =7 \frac{1}{12} [/latex] 2)  [latex]5 \frac{2}{7} -4 \frac{11}{14} = \frac{37}{7} - \frac{67}{14} = \frac{74-67}{14} = \frac{7}{14} = \frac{1}{2} [/latex]