Lời giải:
Gọi biểu thức là $A$. Ta có:
$A=\sqrt{9+20+2.\sqrt{9.20}}+\sqrt{4+5-2\sqrt{20}}-3\sqrt{5}$
$=\sqrt{(\sqrt{9}+\sqrt{20})^2}+\sqrt{(\sqrt{4}-\sqrt{5})^2}-3\sqrt{5}$
$=\sqrt{9}+\sqrt{20}+\sqrt{5}-\sqrt{4}-3\sqrt{5}$
$=1$
Bài 1: Rút gọn
a)\(\sqrt{4+\sqrt{10+2\sqrt{5}}}\)+\(\sqrt{4-\sqrt{10+2\sqrt{5}}}\) ,
b)\(\sqrt{4+\sqrt{15}}\)+\(\sqrt{4-\sqrt{15}}\)-\(2\sqrt{3-\sqrt{5}}\)
c)A=\(\sqrt{4+\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{7+4\sqrt{3}}}}}\)
d)B=\(\sqrt{6+2\sqrt{2}\sqrt{3-\sqrt{\sqrt{2}+\sqrt{12}+\sqrt{18-8\sqrt{2}}}}}\)
e)C=\(\sqrt{\sqrt{5}-\sqrt{3-\sqrt{29-12\sqrt{5}}}}\)
f)D= \(\dfrac{\left(5+4\sqrt{6}\right)\left(49-20\sqrt{6}\right)\left(5-2\sqrt{6}\right)\sqrt{5-2\sqrt{6}}}{9\sqrt{3}-11\sqrt{2}}\)
rut gon bieu thuc a) \(\sqrt{15+2\sqrt{5}-\sqrt[]{21-4\sqrt{5}}}\)
b)\(\sqrt{\sqrt{5}-\sqrt{3-\sqrt{29-12\sqrt{5}}}}\)
Tính thu gọn :
a , \(\sqrt{17-12\sqrt{2}}-\sqrt{17+12\sqrt{2}}\)
b , \(\sqrt{27+12\sqrt{5}}-\sqrt{27-12\sqrt{5}}\)
c , \(\sqrt{15-6\sqrt{6}}+\sqrt{15+\sqrt{6\sqrt{6}}}\)
d , \(\sqrt{4+\sqrt{15}}+\sqrt{4-\sqrt{15}}-2\sqrt{3-\sqrt{5}}\)
e , \(\sqrt{17-3\sqrt{32}}+\sqrt{17+3\sqrt{32}}\)
f , \(\sqrt{5+\sqrt{3-\sqrt{29-12\sqrt{5}}}}\)
Bài 1: Rút gọn
a)\(\sqrt{4+\sqrt{10+2\sqrt{5}}}\)+\(\sqrt{4-\sqrt{10+2\sqrt{5}}}\) ,
b)\(\sqrt{4+\sqrt{15}}\)+\(\sqrt{4-\sqrt{15}}\)-\(2\sqrt{3-\sqrt{5}}\)
c)A=\(\sqrt{4+\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{7+4\sqrt{3}}}}}\)
d)B=\(\sqrt{6+2\sqrt{2}\sqrt{3-\sqrt{\sqrt{2}+\sqrt{12}+\sqrt{18-8\sqrt{2}}}}}\)
e)C=\(\sqrt{\sqrt{5}-\sqrt{3-\sqrt{29-12\sqrt{5}}}}\)
f)D=\(\dfrac{\left(5+2\sqrt{6}\right)\left(49-20\sqrt{6}\right)\left(5-2\sqrt{6}\right)\sqrt{5-2\sqrt{6}}}{9\sqrt{3}-11\sqrt{2}}\)
Mình sửa lại để m.n dễ nhìn hơn!
M=\(\sqrt{9+4\sqrt{5}}-\sqrt{6-2\sqrt{5}}\)
N=\(\sqrt{7-4\sqrt{3}}-\sqrt{12-6\sqrt{3}}\)
tính H = \(\sqrt{5}-\sqrt{3-\sqrt{29-12\sqrt{5}}}\)
\(\sqrt{\sqrt{5}-\sqrt{3-\sqrt{29-12\sqrt{ }}}5}\)
Bài 1 Rút gọn: D = \(\sqrt{\sqrt{5}-\sqrt{\sqrt{3}-\left(29-12\sqrt{5}\right)}}\)
Tính:
a.\(A=\sqrt{4+\sqrt{6-2\sqrt{5}}}\)
b.\(B=\sqrt{13+30\sqrt{2+\sqrt{9+4\sqrt{2}}}}\)
c.\(C=\sqrt{6+2\sqrt{5}-\sqrt{29-12\sqrt{5}}}\)
d.\(D=2\sqrt{4-\sqrt{5+\sqrt{21+\sqrt{80}}}}\)
Giúp em với ạ!