Question

a)
$\sqrt{2} ( \sqrt{2}+\sqrt{3}) -\sqrt{3}( 2\sqrt{3} + \sqrt{2} )$
b)
$( \sqrt{2} - \sqrt{12} )( \sqrt{8} + \sqrt{3} )$

​

Answer 1

Inmultirea cu acelasi radical da acel numar de sub radical

Adica V2 * V2 = V4 = 2

V3* V3 = V9 = 3

a) V4+V6 - 2*V9-V6 = 2-2*3 = 2-6 = -4

b) (V2- 2V3)(2V2+3) = 2V2*V2+3V2 -2V3*2V2-2V3*3 = 2*2+3V2-4V6-6V3 = 4+3V2-4V6-6V3

Answer 2

a)  

$\sqrt{2}(\sqrt{2} +\sqrt{3} )-\sqrt{3} (2\sqrt{3} +\sqrt{2} )=\\=2+\sqrt{6} -2*3-\sqrt{6} =\\=2-6=-4$

b) $(\sqrt{2} -\sqrt{12} )(\sqrt{8} +\sqrt{3} )=\\=\sqrt{16} +\sqrt{6} -\sqrt{96} -\sqrt{36} =\\=4+\sqrt{6} -4\sqrt{6} -6=\\=-2-3\sqrt{6}$