Răspuns:
[tex]mg = 5 \sqrt{5} - 10[/tex]
Explicație pas cu pas:
[tex]a = \frac{ \sqrt{5} }{ \sqrt{5 - 2} } = \frac{ \sqrt{5} }{ \sqrt{3} } = \frac{ \sqrt{15} }{3} \\ b = 5 - \sqrt{20} = > 5 - 2 \sqrt{5} \\ mg = \sqrt{ \frac{15}{3} } \times \frac{5 - 2 \sqrt{5} }{1} = > \frac{ \sqrt{15} }{ \sqrt{3} } \times (5 - 2 \sqrt{5)} = > \frac{ \sqrt{45} }{3} \times (5 - 2 \sqrt{5)} = > \frac{3 \sqrt{5} }{3} \times (5 - 2 \sqrt{5)} = > \sqrt{5} \times (5 - 2 \sqrt{5)} = > 5 \sqrt{5} - 2 \times 5 = > 5 \sqrt{5 } - 10 = > mg = 5 \sqrt{5} - 10[/tex]