Câu 62: Trang 33 - sách giáo khoa (SGK) toán lớp 9 tập 1Rút gọn các biểu thức sau :a....

{
"content1": "a. $\frac{1}{2}\sqrt{48}-2\sqrt{75}-\frac{\sqrt{33}}{\sqrt{11}}+5\sqrt{1\frac{1}{3}}$ = $\frac{1}{2}\sqrt{16\times 3}-2\sqrt{25\times 3}-\frac{\sqrt{11\times 3}}{\sqrt{11}}+5\sqrt{4\times 3}$ = $\frac{1}{2}\times4\sqrt{3}-2\times5\sqrt{3}-\sqrt{3}+5\times2\sqrt{3}$ = $2\sqrt{3}-10\sqrt{3}-\sqrt{3}+10\sqrt{3}$ = $-\sqrt{3}$",
"content2": "b. $\sqrt{150}+\sqrt{1,6}.\sqrt{60}+4,5.\sqrt{2\frac{2}{3}}-\sqrt{6}$ = $\sqrt{25\times 6}+\sqrt{1.6\times60}+4.5\sqrt{2\times \frac{8}{3}}-\sqrt{6}$ = $5\sqrt{6}+\sqrt{96}+4.5\sqrt{16}-\sqrt{6}$ = $5\sqrt{6}+\sqrt{96}+18-\sqrt{6}$ = $5\sqrt{6}+4\sqrt{6}+18$ = $9\sqrt{6}+18$",
"content3": "c. $\left ( \sqrt{28}-2\sqrt{3}+\sqrt{7} \right )\sqrt{7}+\sqrt{84}$ = $(\sqrt{4\times 7}-2\sqrt{3}+\sqrt{7})\sqrt{7}+\sqrt{4\times 21}$ = $(2\sqrt{7}-2\sqrt{3}+\sqrt{7})\sqrt{7}+2\sqrt{21}$ = $(2\sqrt{49}-2\sqrt{21}+\sqrt{7}+2\sqrt{21}$ = $14-2\sqrt{21}+\sqrt{7}+2\sqrt{21}$ = $14+\sqrt{7}$",
"content4": "d. $\left ( \sqrt{6} +\sqrt{5}\right )^{2}-\sqrt{120}$ = $(\sqrt{6}+\sqrt{5})(\sqrt{6}+\sqrt{5})-\sqrt{4\times 30}$ = $(\sqrt{36}+\sqrt{30}+\sqrt{30}+\sqrt{25})-\sqrt{4}\sqrt{30}$ = $(6+2\sqrt{30}+5)-2\sqrt{30}$ = $11$",
"content5": ""
}