Salut!
[tex]8 \sqrt{8} \\ = 8 \sqrt{2 {}^{3} } \\ = 8 \sqrt{2} {}^{2 + 1} \\ = 8 \sqrt{2 {}^{2} \times 2 {}^{1} } \\ = 8 \sqrt{2 {}^{2} \times 2} \\ = 8 \sqrt{2 {}^{2} } \sqrt{2} \\ = 8 \times 2 \sqrt{2} \\ = 16 \sqrt{2} [/tex]
Succes!
