Răspuns:
11.
[tex]a = \sqrt{3} (3 \sqrt{3} + 5 \sqrt{3} - 9 \sqrt{3} ) + 2 \sqrt{3} \times 4 \sqrt{3} = \sqrt{3} \times ( - \sqrt{3} ) + 8 \times 3 = - 3 + 24 = 21[/tex]
[tex]b = \sqrt{2} (4 \sqrt{2} + 5 \sqrt{2} - 7 \sqrt{2} ) - 3 \sqrt{3} \times 2 \sqrt{3 } = \sqrt{2} \times 2 \sqrt{2} - 18 = 4 - 18 = - 14[/tex]
[tex]a + b = 21 + ( - 14) = 7[/tex]
