[tex]zad.1\\\\(a+\sqrt{3} )(a-\sqrt{5} )=a\cdot a -a\cdot\sqrt{5} +a\cdot\sqrt{3} -\sqrt{3} \cdot \sqrt{5} =a^{2} -a\sqrt{5} +a\sqrt{3} - \sqrt{15} =a^{2} +(\sqrt{3} -\sqrt{5} )a-\sqrt{15} \\\\zad.2\\\\(5\sqrt{2} +4\sqrt{3})(5-4\sqrt{3})= (5\sqrt{2})^{2} -(4\sqrt{3})^{2} =25\cdot2 - 16\cdot 3=50-48 = 2\\\\korzysatam~~ze~~wzoru~~skroconego~~mnozenia:\\(a-b)(a+b)=a^{2} -b^{2}[/tex]
