Помогите с дз в) и г) с решением

$..... = \frac{ {2}^{5} \times {7}^{5} \times {2}^{ - 7} }{ {7}^{ - 2} \times {4}^{ - 2} \times {7}^{8} } = \frac{ {2}^{5} \times {7}^{5} \times {7}^{2} \times {4}^{2} }{ {2}^{7} \times {7}^{8} } = \frac{ {2}^{5} \times {7}^{7} \times ({2}^{2}) ^{2} }{ {2}^{7} \times {7}^{8} } = \frac{ {2}^{9} \times {7}^{7} }{ {2}^{7} \times {7}^{8} } = \frac{ {2}^{2} }{7 } = \frac{4}{7}$
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$.... = \frac{ {30}^{6} }{ {10}^{2} \times {15}^{4} } = \frac{ {2}^{6} \times {15}^{6} }{ {2}^{2} \times {5}^{2} \times {15}^{4} } = \frac{ {2}^{4} \times {15}^{2} }{ {5}^{2} } = \frac{ {2}^{4} \times {3}^{2} \times {5}^{2} }{ {5}^{2} } = {2}^{4} \times {3}^{2} = 16 \times 9 = 144$