б) Вычислим ( \frac{(3 \cdot 2^{20} + 7 \cdot 2^{19}) \cdot 52}{(13 \cdot 8^4)^2} = \frac{(3 \cdot 2 \cdot 2^{19} + 7 \cdot 2^{19}) \cdot 4 \cdot 13}{(13 \cdot (2^3)^4)^2} = \frac{2^{19}(6 + 7) \cdot 4 \cdot 13}{(13 \cdot 2^{12})^2} = \frac{2^{19} \cdot 13 \cdot 4 \cdot 13}{13^2 \cdot 2^{24}} = \frac{2^{19} \cdot 4}{2^{24}} = \frac{2^{19} \cdot 2^2}{2^{24}} = \frac{2^{21}}{2^{24}} = \frac{1}{2^{24-21}} = \frac{1}{2^3} = \frac{1}{8} \).
Ответ: 1/8