Question

\(\sqrt{7}\left(\sqrt{7}+\sqrt{\dfrac{4}{7}}-\sqrt{\dfrac{16}{343}}\right)\)

Answer 1

\(=\sqrt{7}\left(\sqrt{7}+\sqrt{\dfrac{4}{7}}-\sqrt{\dfrac{16}{343}}\right)\)

\(=\sqrt{7.7}+\sqrt{\dfrac{4}{7}.7}-\sqrt{\dfrac{16}{343}.7}\)

\(=7+\sqrt{4}-\sqrt{\dfrac{16}{49}}=7+2-\dfrac{4}{7}=\dfrac{59}{7}\)

Answer 2

\(=\sqrt{7^2}+\sqrt{7\cdot\dfrac{4}{7}}-\sqrt{7\cdot\dfrac{16}{343}}\)

\(=7+2-\dfrac{4}{7}=9-\dfrac{4}{7}=\dfrac{59}{7}\)