Réponse:
1)
[tex] \frac{5 \sqrt{72} - 3 \sqrt{8} }{7 \sqrt{2} } = \frac{5 \sqrt{9 \times 4 \times 2} - 3 \sqrt{4 \times 2} }{7 \sqrt{2} } \\ = \frac{5 \times 3 \times 2 \sqrt{2} - 3 \times 2 \sqrt{2} }{7 \sqrt{2} } \\ = \frac{30 \sqrt{2} - 6 \sqrt{2} }{7 \sqrt{2} } \\ = \frac{24 \sqrt{2} }{7 \sqrt{2} } = \frac{24}{7} \\ \\ 2) \frac{ \sqrt{48} + \sqrt{12} }{ \sqrt{27} } = \frac{ \sqrt{4 \times 3 \times 4} + \sqrt{4 \times 3} }{ \sqrt{9 \times 3} } \\ = \frac{4 \sqrt{3} + 2 \sqrt{3} }{3 \sqrt{3} } \\ = \frac{6 \sqrt{3} }{3 \sqrt{3} } = \frac{6}{3} = 2 [/tex]
