Bài 7: Biến đối đơn giản biểu thức chứa căn bậc hai (Tiếp theo)
Các câu hỏi tương tự
chỉ cần đưa về dạng hằng đảng thức thôi , xin cam ơn mọi người
1,sqrt{26+15sqrt{3}}
2,sqrt{8-2sqrt{15}}-sqrt{23-4sqrt{5}}
3,sqrt{12-3sqrt{7}}-sqrt{12-3sqrt{7}}
4,sqrt{7-2sqrt{10}}-sqrt{7+2sqrt{10}}
5,sqrt{4+sqrt{10+2sqrt{5}}}+sqrt{4-sqrt{10+2sqrt{5}}}
6,3sqrt{3}+4sqrt{12}-5sqrt{27}
7,sqrt{32}-sqrt{50}+sqrt{18}
8,sqrt{72}+sqrt{4dfrac{1}{2}}-sqrt{32}-sqrt{162}
9,dfrac{1}{2}sqrt{48}-2sqrt{75}-dfrac{sqrt{33}}{sqrt{11}}+5sqrt{1dfrac{1}{3}}
Đọc tiếp
chỉ cần đưa về dạng hằng đảng thức thôi , xin cam ơn mọi người
1,\(\sqrt{26+15\sqrt{3}}\)
2,\(\sqrt{8-2\sqrt{15}}-\sqrt{23-4\sqrt{5}}\)
3,\(\sqrt{12-3\sqrt{7}}-\sqrt{12-3\sqrt{7}}\)
4,\(\sqrt{7-2\sqrt{10}}-\sqrt{7+2\sqrt{10}}\)
5,\(\sqrt{4+\sqrt{10+2\sqrt{5}}}+\sqrt{4-\sqrt{10+2\sqrt{5}}}\)
6,\(3\sqrt{3}+4\sqrt{12}-5\sqrt{27}\)
7,\(\sqrt{32}-\sqrt{50}+\sqrt{18}\)
8,\(\sqrt{72}+\sqrt{4\dfrac{1}{2}}-\sqrt{32}-\sqrt{162}\)
9,\(\dfrac{1}{2}\sqrt{48}-2\sqrt{75}-\dfrac{\sqrt{33}}{\sqrt{11}}+5\sqrt{1\dfrac{1}{3}}\)
1. dfrac{-2}{sqrt{3}-1}2. dfrac{5}{1-sqrt{6}}3. dfrac{2+sqrt{5}}{2-sqrt{5}}4. dfrac{1}{5+2sqrt{6}}5. dfrac{sqrt{5}+2}{sqrt{5}-2}6. dfrac{5sqrt{2}-2sqrt{5}}{sqrt{2}-sqrt{5}}7. dfrac{sqrt{20}-3sqrt{10}}{3-sqrt{2}}8. dfrac{6-2sqrt{5}}{3+sqrt{5}}9. dfrac{9+4sqrt{5}}{sqrt{5}+2}
Đọc tiếp
1. \(\dfrac{-2}{\sqrt{3}-1}\)
2. \(\dfrac{5}{1-\sqrt{6}}\)
3. \(\dfrac{2+\sqrt{5}}{2-\sqrt{5}}\)
4. \(\dfrac{1}{5+2\sqrt{6}}\)
5. \(\dfrac{\sqrt{5}+2}{\sqrt{5}-2}\)
6. \(\dfrac{5\sqrt{2}-2\sqrt{5}}{\sqrt{2}-\sqrt{5}}\)
7. \(\dfrac{\sqrt{20}-3\sqrt{10}}{3-\sqrt{2}}\)
8. \(\dfrac{6-2\sqrt{5}}{3+\sqrt{5}}\)
9. \(\dfrac{9+4\sqrt{5}}{\sqrt{5}+2}\)
Giải 5 câu sau:
1. \(\dfrac{\sqrt{5}+2}{\sqrt{5}-2}\)
2. \(\dfrac{5\sqrt{2}-2\sqrt{5}}{\sqrt{2}-\sqrt{5}}\)
3. \(\dfrac{\sqrt{20}-3\sqrt{10}}{3-\sqrt{5}}\)
4. \(\dfrac{6-2\sqrt{5}}{3+\sqrt{5}}\)
5. \(\dfrac{9+4\sqrt{5}}{\sqrt{5}+2}\)
Khử mẫu của biểu thức lấy căn:
\(\sqrt{\dfrac{1}{600}};\sqrt{\dfrac{11}{540}};\sqrt{\dfrac{3}{50}};\sqrt{\dfrac{5}{98}};\sqrt{\dfrac{\left(1-\sqrt{3}\right)^2}{27}}.\)
B1: thực hiện phép tínha )dfrac{sqrt{6}-sqrt{15}}{sqrt{35}-sqrt{14}}b ) dfrac{10+2sqrt{10}}{sqrt{5}+sqrt{2}}+dfrac{8}{1-sqrt{5}}c )dfrac{sqrt{3-sqrt{5}.}left(3+sqrt{5}right)}{sqrt{10}+sqrt{2}}d ) dfrac{1}{sqrt{2}+sqrt{2+sqrt{3}}}+dfrac{1}{sqrt{2}-sqrt{2+sqrt{3}}}B2:chúng minh vế phải bằng vế trái a) dfrac{21+8sqrt{5}}{4+sqrt{5}}.sqrt{9-4sqrt{5}}sqrt{5}-2 b) sqrt{8-2sqrt{15}}-sqrt{8+2sqrt{15}}-2sqrt{3}
Đọc tiếp
B1: thực hiện phép tính
a )\(\dfrac{\sqrt{6}-\sqrt{15}}{\sqrt{35}-\sqrt{14}}\)
b ) \(\dfrac{10+2\sqrt{10}}{\sqrt{5}+\sqrt{2}}+\dfrac{8}{1-\sqrt{5}}\)
c )\(\dfrac{\sqrt{3-\sqrt{5}.}\left(3+\sqrt{5}\right)}{\sqrt{10}+\sqrt{2}}\)
d ) \(\dfrac{1}{\sqrt{2}+\sqrt{2+\sqrt{3}}}+\dfrac{1}{\sqrt{2}-\sqrt{2+\sqrt{3}}}\)
B2:chúng minh vế phải bằng vế trái
a) \(\dfrac{21+8\sqrt{5}}{4+\sqrt{5}}.\sqrt{9-4\sqrt{5}}=\sqrt{5}-2\)
b) \(\sqrt{8-2\sqrt{15}}-\sqrt{8+2\sqrt{15}}=-2\sqrt{3}\)
Rút gọn
\(A=\dfrac{1+\sqrt{5}}{\sqrt{2}+\sqrt{3+\sqrt{5}}}+\dfrac{1-\sqrt{5}}{\sqrt{2}-\sqrt{3-\sqrt{5}}}\)
\(B=\dfrac{1}{\sqrt{1}-\sqrt{2}}+\dfrac{1}{\sqrt{2}-\sqrt{3}}+....+\dfrac{1}{\sqrt{n-1}-\sqrt{n}}\) (n thuộc N, n>=2)
Rút gọn
1, 2sqrt{5}-sqrt{125}-sqrt{80}
2, 3sqrt{2}-sqrt{8}+sqrt{50}-4sqrt{32}
3, sqrt{18}-3sqrt{80}-2sqrt{50}+2sqrt{45}
4, sqrt{27}-2sqrt{3}+2sqrt{48}-3sqrt{75}
5, 3sqrt{2}-4sqrt{18}+sqrt{32}-sqrt{50}
6, 2sqrt{3}-sqrt{75}+2sqrt{12}-sqrt{147}
7, sqrt{20}-2sqrt{45}-3sqrt{80}+sqrt{125}
8, 6sqrt{12}-sqrt{20}-2sqrt{27}+sqrt{125}
9, 4sqrt{24}-2sqrt{54}+3sqrt{6}-sqrt{150}
10, 2sqrt{18}-3sqrt{80}-5sqrt{147}+5sqrt{245}-3sqrt{98}
Các bạn ơi !! giúp mik với đi !!!!!
Đọc tiếp
Rút gọn
1, \(2\sqrt{5}-\sqrt{125}-\sqrt{80}\)
2, \(3\sqrt{2}-\sqrt{8}+\sqrt{50}-4\sqrt{32}\)
3, \(\sqrt{18}-3\sqrt{80}-2\sqrt{50}+2\sqrt{45}\)
4, \(\sqrt{27}-2\sqrt{3}+2\sqrt{48}-3\sqrt{75}\)
5, \(3\sqrt{2}-4\sqrt{18}+\sqrt{32}-\sqrt{50}\)
6, \(2\sqrt{3}-\sqrt{75}+2\sqrt{12}-\sqrt{147}\)
7, \(\sqrt{20}-2\sqrt{45}-3\sqrt{80}+\sqrt{125}\)
8, \(6\sqrt{12}-\sqrt{20}-2\sqrt{27}+\sqrt{125}\)
9, \(4\sqrt{24}-2\sqrt{54}+3\sqrt{6}-\sqrt{150}\)
10, \(2\sqrt{18}-3\sqrt{80}-5\sqrt{147}+5\sqrt{245}-3\sqrt{98}\)
Các bạn ơi !! giúp mik với đi !!!!!
Tính:
a, A= \(\sqrt{\dfrac{3+\sqrt{5}}{3-\sqrt{5}}}\)+ \(\sqrt{\dfrac{3-\sqrt{5}}{3+\sqrt{5}}}\)
b, B= \(\dfrac{3+\sqrt{5}}{2\sqrt{2}+\sqrt{3+\sqrt{5}}}\)+ \(\dfrac{3-\sqrt{5}}{2\sqrt{2}-\sqrt{3-\sqrt{5}}}\)
c, C= \(\dfrac{1}{2\sqrt{1}+1\sqrt{2}}+\dfrac{1}{3\sqrt{2}+2\sqrt{3}}+...+\dfrac{1}{25\sqrt{24}+24\sqrt{25}}\)
Rút gọn biểu thức
\(a.\dfrac{\sqrt{5}-2\sqrt{3}}{\sqrt{5}+\sqrt{3}}-\dfrac{2\sqrt{5}+\sqrt{3}}{\sqrt{5}-\sqrt{3}}\)
\(b.x\sqrt{2x+2}+\left(x+1\right)\sqrt{\dfrac{2}{x+1}}-4\sqrt{\dfrac{x+1}{2}}\)