7 класс,не могу решить.ПОМОГИТЕ

Решение:
${20}^{3} \times {0.5}^{3} = \frac{ {20}^{3} }{1} \times ({ \frac{10}{20} )}^{3} = \frac{ {20}^{3} \times {10}^{3} }{1 \times {20}^{3} } = {10}^{3} = 1000\\ \frac{4 \times {2}^{5} }{ {2}^{7} } = \frac{ {2}^{2} \times {2}^{5} }{ {2}^{7} } = \frac{ {2}^{7} }{ {2}^{7} } = 1 \\ {(0.25)}^{2} \times {100}^{2} = \frac{ {25}^{2} \times {100}^{2} }{ {100}^{2} } = {25}^{2} = 625\\ \frac{ {3}^{8} }{ {3}^{6} \times 9 } = \frac{ {3}^{8} }{ {3}^{6} \times {3}^{2} } = \frac{ {3}^{8} }{ {3}^{8} } = 1$