Question

Simplify this question
(m+n/7)^3 (m-n/7)

Answer 1

${( \frac{m + n}{7}) }^{3} ( \frac{m - n}{7} ) \\ \\ = \frac{1}{ {7}^{4} } (m - n)(m + n) {(m + n)}^{2} \\ \\ = \frac{1}{ {7}^{4} } ( {m}^{2} - {n}^{2} )( {m}^{2} + {n}^{2} + 2mn) \\ \\ = \frac{ {m}^{4} - {n}^{4} + 2 {m}^{3}n - 2m {n}^{3} }{ {7}^{4} }$

hope it helps