rút gọn các biểu thức sau
a) \(\frac{4}{\sqrt{10}}\left(\sqrt{3+\sqrt{5}}+\sqrt{3-\sqrt{5}}\right)\)
b)\(\left(4+\sqrt{\text{15}}\right).\left(\sqrt{10}-\sqrt{6}\right).\sqrt{\text{4}-\sqrt{15}}\)
c)\(\sqrt{\text{4 }\sqrt{\text{6}}\text{ }+8\sqrt{\text{3 }}+4\sqrt{2}+18}\)
Giải phương trình sau:
\(1,\sqrt{x-2}-\sqrt{x+1}=\sqrt{2\text{x}-1}-\sqrt{x+3}\)
\(2,x^2-6\text{x}+26=6\sqrt{2\text{x}+1}\)
\(3,\left(\sqrt{x+5}-\sqrt{x-2}\right)\left(1+\sqrt{x^2+7\text{x}+10}\right)=3\)
4,\(\sqrt[3]{x-4}-\sqrt{9-x}=-1\)
5,\(\left(x+1\right)\sqrt{16\text{x}+17}=8\text{x}^2-15\text{x}-23\)
Giúp mình với ạ mình đang cần gấp <3
Tính \(A=x+y\), biết: \(\left(\sqrt{x^2+\text{5}}+x\right)\left(\sqrt{y^2+\text{5}}+y\right)=\text{5}\)
\(\sqrt{x-1}+\sqrt{x+3}+2\sqrt{\left(x-1\right)\left(x^2-3\text{x}+5\right)}=4-2\text{x}\)
giải phương trình:
\(x^2-2\text{x}-5=\left(3-2\text{x}\right)\sqrt{x-1}\)
\(\text{Cho }a,b,c>0\text{ thỏa mãn }a+b+c=3\)
\(\text{CMR: }\frac{1+b}{1+4a^2}+\frac{1+c}{1+4b^2}+\frac{1+a}{1+4c^2}\ge\frac{6}{5}\)
giải hpt:\(\left\{{}\begin{matrix}\dfrac{4}{x+y}+3\sqrt{4\text{x}-8}=14\\\dfrac{5-x-y}{x+y}-2\sqrt{x-2}=\dfrac{-5}{2}\end{matrix}\right.\)
\(\text{Tính }A=x^2\left(x+1\right)-y^2\left(y-1\right)+xy-3xy\left(x-y+1\right)+2019\) \(\text{biết }x-y=\sqrt{12\sqrt{5}+29}\)
rút gọn
a) \(\frac{7\sqrt{2}+2\sqrt{7}}{\sqrt{14}}-\frac{5}{\sqrt{7}+\sqrt{5}}\)
b) \(\frac{\sqrt{2}\left(3+\sqrt{5}\right)}{2\sqrt{2}+\sqrt{3+\sqrt{5}}}+\frac{\sqrt{2}\left(3-\sqrt{5}\right)}{2\sqrt{2}-\sqrt{3-\sqrt{5}}}\)
c) \(\sqrt[3]{16-8\sqrt{5}}+\sqrt[3]{16\text{ }+8\sqrt{5}}\)
helppp mee