Câu 4: Trang 33 sách VNEN 9 tập 1Thực hiện phép tính:a)$\left ( \sqrt{\frac{9}{2}} +...

{
"content1": "a) $\left ( \sqrt{\frac{9}{2}} + \sqrt{\frac{1}{2}} - \sqrt{2} \right )$.$\sqrt{2}$ = $\sqrt{4} + \sqrt{1} - \sqrt{8} = 2 + 1 - 2\sqrt{2} = 3 - 2\sqrt{2}$",
"content2": "b) ($\sqrt{3}$ - $\sqrt{2}$ + 1)($\sqrt{3}$ - 1) = ($\sqrt{3}$*$\sqrt{3}$ + $\sqrt{3}$*(-1) - $\sqrt{2}$*$\sqrt{3}$ + $\sqrt{3}$ - $\sqrt{2}$ + 1) = 3 - $\sqrt{6}$ + $\sqrt{3}$ - $\sqrt{2}$ + 1 = 4 - $\sqrt{6}$ + $\sqrt{3}$ - $\sqrt{2}$",
"content3": "c) $(\sqrt{2} + \sqrt{5})^{2}$ = $\sqrt{2}^{2}$ + 2*$\sqrt{2}$*$\sqrt{5}$ + $\sqrt{5}^{2}$ = 2 + 2$\sqrt{10}$ + 5 = 7 + 2$\sqrt{10}$",
"content4": "d) ($\sqrt{8}$ - 5$\sqrt{2}$ + $\sqrt{20}$).$\sqrt{5}$ - ($3\sqrt{\frac{1}{10}} + 10$) = ($2\sqrt{2} - 5\sqrt{2} + 2\sqrt{5}$)$\sqrt{5}$ - ($3\sqrt{\frac{1}{10}} + 10) = ($-3\sqrt{2} + 2\sqrt{5}$)$\sqrt{5}$ - ($3\sqrt{\frac{1}{10}} + 10) = $-3\sqrt{10} + 10\sqrt{5} - 3\sqrt{10} - 10 = 7\sqrt{5} - 20$"
}