817 Вправа 817Алгебра 8 клас Бевз 2025 · § 16 · стор. 155

817. Виконай дії.

а) ${\displaystyle (\sqrt{30}+\sqrt{24})\cdot \sqrt{6}-6\sqrt{5}}$=

=${\displaystyle \sqrt{180}+\sqrt{144}-6\sqrt{5}}$=

=${\displaystyle 6\sqrt{5}+12-6\sqrt{5}=}$${\displaystyle 12}$;

б) ${\displaystyle (\sqrt{60}-2\sqrt{45})\cdot \sqrt{15}+\sqrt{2700}}$=

=${\displaystyle \sqrt{900}-2\sqrt{675}+\sqrt{2700}}$=

=${\displaystyle 30-30\sqrt{3}+30\sqrt{3}=}$${\displaystyle 30}$;

в) ${\displaystyle (\sqrt{125}-2\sqrt{5})\cdot \sqrt{10}+\sqrt{32}}$=

=${\displaystyle \sqrt{1250}-2\sqrt{50}+\sqrt{32}}$=

=${\displaystyle 25\sqrt{2}-10\sqrt{2}+4\sqrt{2}=}$${\displaystyle 19\sqrt{2}}$;

г) ${\displaystyle (7\sqrt{3}+\sqrt{6})\cdot \sqrt{6}-\sqrt{800}}$=

=${\displaystyle 7\sqrt{18}+6-\sqrt{800}}$=

=${\displaystyle 21\sqrt{2}+6-20\sqrt{2}=}$${\displaystyle \sqrt{2}+6}$.