Question

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Answer 1

$2m( {7m}^{2} - 20mn - 10m) \div 10m = \\ \frac{2m( {7m}^{2} - 20mn - 10m)}{10} \times m = \\ \frac{m( {7m}^{2} - 20mn - 10m)}{5} \times m = \\ \frac{ {m}^{2} ( {7m}^{2} - 20mn - 10m)}{5} = \\ \frac{7 {m}^{4} - 20 {m}^{3}n - 10 {m}^{3} }{5}$