ж) $$4 \frac{11}{15} + y = 2 \frac{7}{12}$$
$$y = 2 \frac{7}{12} - 4 \frac{11}{15} = \frac{31}{12} - \frac{71}{15} = \frac{31 \cdot 5}{12 \cdot 5} - \frac{71 \cdot 4}{15 \cdot 4} = \frac{155}{60} - \frac{284}{60} = -\frac{129}{60} = -2 \frac{9}{60} = -2 \frac{3}{20}$$
Ответ: $$-2\frac{3}{20}$$