Đáp án + Giải thích các bước giải:
`1)(4-\sqrt{15})(\sqrt{10}-sqrt{6})\sqrt{4-\sqrt{15}}`
`=(4-\sqrt{15}).(\sqrt{5}-\sqrt{3}).\sqrt{8-2\sqrt{15}`
`=(4\sqrt{5}-4\sqrt{3}-5\sqrt{3}-3\sqrt{5}).\sqrt{(\sqrt{5}-sqrt{3})^2`
`=(\sqrt{5}-9\sqrt{3}).(\sqrt{5}-\sqrt{3})`
`=5-\sqrt{15}-9\sqrt{15}+27=32-10\sqrt{13}`
`text{#Study Well}`
Đáp án:
2
Giải thích các bước giải:
\(\begin{array}{l}\left( {4 + \sqrt {15} } \right).\sqrt 2 .\left( {\sqrt 5 - \sqrt 3 } \right).\sqrt {4 - \sqrt {15} } \\ = \left( {4 + \sqrt {15} } \right)\left( {\sqrt 5 - \sqrt 3 } \right)\sqrt {8 - 2\sqrt {15} } \\ = \left( {4 + \sqrt {15} } \right)\left( {\sqrt 5 - \sqrt 3 } \right)\sqrt {5 - 2.\sqrt 5 .\sqrt 3 + 3} \\ = \left( {4 + \sqrt {15} } \right)\left( {\sqrt 5 - \sqrt 3 } \right)\sqrt {{{\left( {\sqrt 5 - \sqrt 3 } \right)}^2}} \\ = \left( {4 + \sqrt {15} } \right){\left( {\sqrt 5 - \sqrt 3 } \right)^2}\\ = \left( {4 + \sqrt {15} } \right)\left( {8 - 2\sqrt {15} } \right)\\ = 2\left( {4 + \sqrt {15} } \right)\left( {4 - \sqrt {15} } \right)\\ = 2\left( {16 - 15} \right) = 2\end{array}\)
A. Choose the correct words or phrases that best complete the passage. Dear Jane, I'm sorry for not (31) ______ to you for two months. In my postcard sent to you when I was on vacation in July, I told you about a new friend of (32) ____, Lisa Moran, who lives near my uncle's farm in Napan Valley, California. You may be curious to know what she is (33) ______. Well, Lisa is of our age - 17 - and not very tall or slim. In fact, she has (34) ______ rounded shoulders and a plump face. The best (35) ______ on Lisa's face are her green eyes and the two dimples on her checks. She (36) ______ lively with her hair cut short and dressed in (37) ______ clothes - jeans and a Tshirt. When I first met her at my cousin's birthday party, I was attracted by her (38) ______ and pleasingly direct manners. Curiously enough, Lisa has the same (39) ______ in music as you and I. That's (40) ______ about Lisa for the moment. How have you been doing with your school work? Please write soon. Best wishes Ann Maxfield 31. a. write b. to write c. writing d. wrote 32. a. I b. me c. my d. mine 33. a. looking b. like c. seen d. simila 34. a. slightly b. hardly c. scarcely d. reasonably 35. a. aspects b. points c. features d. marks 36. a. feels b. seems c. appears d. looks 37. a. casual b. formal c. sports d. trendy 38. a. light-hearted b. high-handed c. self-centered d. easy-going 39. a. taste b. hearing c. sense d. way 40. a. all b. enough c. end d. most
lại giúp tiếp vì tui dốt hình học
Trục căn thức ở mẫu và rút gọn: E = $\frac{1}{\sqrt{10}+\sqrt{15}+\sqrt{14}+\sqrt{21}}$
cold/ they/ when/ often/ volleyball/ it/ play/ is/ do? ko giải thích nha
hjc hjc tranh tui xấu thế sao , mà không 1 ai khen tranh tui xênh thế :<<<< đậu khóc / tủi thân
tính khối lượng bằng gam của nguyên tử sau K, Ca, Cr, S, Fe
helppppppppppppppppppppppppppppppppp
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