\(\sqrt{\frac{81}{9}}\)+ \(\sqrt{\frac{64}{4}}\)
=\(\sqrt{9}\)+ \(\sqrt{16}\)
= 3+4
=7
k nhé
\(\sqrt{\frac{81}{9}}\)+ \(\sqrt{\frac{64}{4}}\)
=\(\sqrt{9}\)+ \(\sqrt{16}\)
= 3+4
=7
k nhé
\(\frac{1-\frac{1}{\sqrt{49}}+\frac{1}{49}-\frac{1}{\left(7\sqrt{7}\right)^2}}{\frac{\sqrt{64}}{2}-\frac{4}{7}+\left(\frac{2}{7}\right)^2-\frac{4}{343}}\)
Rút gọn biểu thức
tính:\(\frac{1}{\sqrt{1}-\sqrt{2}}-\frac{1}{\sqrt{2}-\sqrt{3}}+\frac{1}{\sqrt{3}-\sqrt{4}}-\frac{1}{\sqrt{4}-\sqrt{5}}+\frac{1}{\sqrt{5}-\sqrt{6}}-\frac{1}{\sqrt{6}-\sqrt{7}}+\frac{1}{\sqrt{7}-\sqrt{8}}-\frac{1}{\sqrt{8}-\sqrt{9}}\)
\(\sqrt{2-x^2}+\sqrt{2-\frac{1}{x^2}}=4-\left(x+\frac{1}{x}\right)\)
\(\sqrt{8+x^3}+\sqrt{64-x^3}=x^4-8x^2+28\)
\(\sqrt{x-3}+\sqrt{5-x}=x^2-8x+18\)
Toán 8 nâng cao
1/ \(\sqrt{\frac{m}{1-2x+x^2}}\cdot\sqrt{\frac{4m-8mx+4mx^2}{81}}\)
2/\(\left(\frac{1-a\sqrt{a}}{1-\sqrt{a}}+\sqrt{a}\right)\left(\frac{1-\sqrt{a}}{1-a}\right)^2\)
3/\(\frac{a+b}{b^2}\sqrt{\frac{a^2b^4}{a^2+2ab+b^2}}\)
Tính :
a ) \(S=\frac{1}{\sqrt{1}\sqrt{3}}+\frac{1}{\sqrt{3}+\sqrt{5}}+\frac{1}{\sqrt{5}+\sqrt{7}}+.....+\)\(\frac{1}{\sqrt{2017}+\sqrt{2019}}\)
b ) \(S=\frac{1}{\sqrt{2}+\sqrt{4}}+\frac{1}{\sqrt{4}+\sqrt{6}}+....+\frac{1}{\sqrt{100}+\sqrt{102}}\)
c ) \(S=\frac{1}{\sqrt{1}+\sqrt{2}}+\frac{1}{\sqrt{2}+\sqrt{3}}+.....+\frac{1}{\sqrt{100}+\sqrt{101}}\)
d ) \(S=\frac{1}{\sqrt{3}+\sqrt{6}}+\frac{1}{\sqrt{6}+\sqrt{9}}+\frac{1}{\sqrt{9}+\sqrt{12}}+....+\frac{1}{\sqrt{2016}+\sqrt{2019}}\)
Bài 1: Tính giá trị của biểu thức:
1)\(H=\sqrt[3]{3+\sqrt{9+\frac{125}{7}}}-\sqrt[3]{-3+\sqrt{9+\frac{125}{7}}}\)
2)\(P=\frac{2}{\sqrt{4-3\sqrt[4]{5}+2\sqrt{5}-\sqrt[4]{125}}}\)
Bài 2: Tính giá trị biểu thức: \(Q=\sqrt[10]{\frac{19+6\sqrt{10}}{2}}.\sqrt[5]{3\sqrt{2}-2\sqrt{5}}\)
\(K=\frac{\sqrt{\sqrt[4]{8}+\sqrt{\sqrt{2}-1}}-\sqrt{\sqrt[4]{8}-\sqrt{\sqrt{2}-1}}}{\sqrt{\sqrt[4]{8}-\sqrt{\sqrt{2}+1}}}\)
Tính \(C=\sqrt{x}+\frac{\sqrt[3]{2-\sqrt{3}}.\sqrt[6]{7+4\sqrt{3}}-x}{\sqrt[4]{9-4\sqrt{5}}.\sqrt{2+\sqrt{5}}+\sqrt{x}}\)
\(A=\frac{\sqrt{3.\sqrt{18.\sqrt[6]{8.\sqrt{x.64^{2\sqrt{7}}}}}}}{\sqrt{y}.6.z^{7\sqrt{2}}.10+\sqrt[15]{78}}=\frac{95}{78}\)
Tìm x,y,z và x+y+z
Rút gọn
1) \(B=\sqrt{\sqrt{7}+6+\sqrt{13-2\sqrt{64-6\sqrt{7}}}}\)
2) \(C=\sqrt{4+\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{7+4\sqrt{3}}}}}\)
3) \(D=\frac{2\sqrt{3+\sqrt{5-\sqrt{13+\sqrt{48}}}}}{\sqrt{6}+\sqrt{2}}\)