A=13−2√42
=7-2\(\sqrt{6}.\sqrt{7}\)+6
=\(\left(\sqrt{7}-\sqrt{6}\right)^2\)
=>\(\sqrt{A}=\sqrt{7}-\sqrt{6}\)
A=46+6√5
=45+2.\(3\sqrt{5}\)+1
=(\(3\sqrt{5}+1\))2
=>\(\sqrt{A}=3\sqrt{5}+1\)
1) Tính
a) \(\sqrt{46-6\sqrt{5}}-\sqrt{29-12\sqrt{5}}\)
b) \(\sqrt{13-\sqrt{160}}-\sqrt{53+4\sqrt{90}}\)
c) \(\left(3-\sqrt{2}\right)\sqrt{7+4\sqrt{3}}\)
d) \(\left(\sqrt{7}-\sqrt{3}\right)\sqrt{10+2\sqrt{21}}\)
e) \(\left(3\sqrt{2}+10\right)\sqrt{38-12\sqrt{5}}\)
Rút gọn biểu thức
A. (2-√3)\(\sqrt{7+4\sqrt{3}}\)
B. \(\sqrt{13+4\sqrt{10}}\:+\:\sqrt[]{13-4\sqrt{10}}\)
C.(3 - √2) \(\sqrt{11+6\sqrt{2}}\)
D. (√5+√7) \(\sqrt{12-2\sqrt{35}}\)
E. (√2-√9)\(\sqrt{11+2\sqrt{18}}\)
F. \(\sqrt{46-6\sqrt{5}}\:+\:\sqrt{29-12\sqrt{5}}\)
G.\(\sqrt{49-5\sqrt{96}}\:+\:\sqrt{49+5\sqrt{96}}\)
H.\(\sqrt{13-\sqrt{160\:\:\:\:}}\:+\:\sqrt{53+4\sqrt{90}}\)
Rút gọn:
a)\(\dfrac{\sqrt{a}+a\sqrt{b}-\sqrt{b}-b\sqrt{a}}{ab-1}\)
b) \(\dfrac{2\sqrt{15}-2\sqrt{10}+\sqrt{6}-3}{2\sqrt{5}-2\sqrt{10}-\sqrt{3}+\sqrt{6}}\)
Tính :
a) A= \(\sqrt{\sqrt{3}+\sqrt{2}}.\sqrt{\sqrt{3}-\sqrt{2}}\)
b) B=\(\sqrt{5-2\sqrt{6}}+\sqrt{5+2\sqrt{6}}\)
c) C= \(3-\sqrt{3-\sqrt{5}}\)
B2: rút gọn:
a, \((\sqrt{14}+\sqrt{6})(\sqrt{5}-\sqrt{21})\)
b, A= \(\sqrt{7+\sqrt{15}}-\sqrt{7-\sqrt{13}}\)
giúp em với ạ , em cảm ơn nhiều
Tính
1) \(\sqrt{18}.\sqrt{2}\)
2) \(\sqrt{15^2-9^2}\)
3) \(\sqrt{46-6\sqrt{5}}-\sqrt{46+6\sqrt{5}}\)
4)\(\sqrt{21+6\sqrt{6}}-\sqrt{21-6\sqrt{6}}\)
5) \(\left(2+\sqrt{5}\right).\sqrt{9-4\sqrt{5}}\)
6)\(\left(3-\sqrt{2}\right).\sqrt{7+4\sqrt{3}}\)
7)\(\left(\sqrt{3}+\sqrt{5}\right).\sqrt{7-2\sqrt{10}}\)
8)\(\left(\sqrt{6}+\sqrt{10}\right).\sqrt{4-\sqrt{15}}\)
9) \(\sqrt{2}.\left(\sqrt{8}-\sqrt{32}+3\sqrt{18}\right)\)
10) \(\sqrt{2}\left(\sqrt{2}-\sqrt{3-\sqrt{5}}\right)\)
11) \(\sqrt{3}-\sqrt{2}-\sqrt{\left(\sqrt{3}+\sqrt{2}\right)^2}\)
12) \(\left(\sqrt{2}-\sqrt{3+\sqrt{5}}\right).\sqrt{2}+2\sqrt{5}\)
1)Tính:
a)(\(\sqrt{3-\sqrt{5}}+\sqrt{3+\sqrt{5}}\))\(^2\) b)\(\sqrt{2-\sqrt{3}-\sqrt{2+\sqrt{3}}}\) c)\(\frac{\sqrt{10}+\sqrt{6}}{2\sqrt{5}+\sqrt{12}}\) d)\(\sqrt{8-2\sqrt{15}-\sqrt{8+2\sqrt{15}}}\) e)\(\sqrt{\left(1-\sqrt{2007}\right)^2}.\sqrt{2008+2\sqrt{2007}}\)
b1. Rút gọn
a)\(\frac{5\sqrt{6}+6\sqrt{5}}{\sqrt{5}+\sqrt{6}}\)
b) \(\frac{2\sqrt{7}-4\sqrt{3}}{3\sqrt{35}-6\sqrt{15}}\)
c) \(\frac{12\sqrt{10}-16\sqrt{14}}{6\sqrt{5}-8\sqrt{7}}\)
d) \(\frac{6\sqrt{6}-27}{2\sqrt{2}-3\sqrt{3}}\)
e) \(\frac{-4\sqrt{2}+3\sqrt{5}}{-2\sqrt{10}}\)
Tính
a) \(\sqrt{\left(4-2\sqrt{3}\right).\left(13+4\sqrt{3}\right)}\)
b) \(\left(\sqrt{3}-2\right).\left(\sqrt{6}+\sqrt{2}\right).\sqrt{\sqrt{3}+2}\)
c)\(\left(3+\sqrt{5}\right).\left(\sqrt{10}-\sqrt{2}\right).\sqrt{3-\sqrt{5}}\)
d) \(\left(4+\sqrt{15}\right).\left(\sqrt{10}-\sqrt{6}\right).\sqrt{4-\sqrt{15}}\)
Giúp mk với, mk hứa sẽ tick cho.Cảm ơn nhiều!!