ĐKXĐ: ...
Đặt \(\sqrt{x-\frac{1}{4x}}=a>0\Rightarrow-\frac{1}{4x}=a^2-x\)
Pt trở thành:
\(\sqrt{x^2+a^2-x}+a=x\)
\(\Leftrightarrow\sqrt{x^2+a^2-x}=x-a\) (\(x\ge a\))
\(\Rightarrow x^2+a^2-x=x^2+a^2-2ax\)
\(\Leftrightarrow x=2ax\Rightarrow a=\frac{1}{2}\)
\(\Rightarrow x-\frac{1}{4x}=\frac{1}{4}\Leftrightarrow4x^2-x-1=0\Rightarrow x=\frac{1+\sqrt{17}}{8}\)
P = 1 - \(\left(\frac{2}{\sqrt{x}+2}-\frac{5\sqrt{x}}{4x-1}+\frac{1}{1-2\sqrt{x}}\right):\frac{\sqrt{x}-1}{4x+4\sqrt{x}+1}\)
rút gọn P
a. A=(\(\frac{3x+16\sqrt{x}-7}{x+2\sqrt{x}-3}-\frac{\sqrt{x}+1}{\sqrt{x}+3}-\frac{\sqrt{x}+7}{\sqrt{x}-1}\)) : (\(2-\frac{\sqrt{x}}{\sqrt{x}-1}\))
b. B=(\(\frac{\sqrt{x}+1}{\sqrt{xy}+1}+\frac{\sqrt{xy}+\sqrt{x}}{1-\sqrt{xy}}+1\)) :( 1-\(\frac{\sqrt{xy}+\sqrt{x}}{\sqrt{xy}-1}-\frac{\sqrt{x}+1}{\sqrt{xy}+1}\))
c. C=( \(\frac{\sqrt{x}-4x}{1+4x}-1\)):(\(\frac{1+2x}{1-4x}-\frac{2\sqrt{x}}{2\sqrt{x}}-1\))
d. D=(\(\frac{\sqrt{a-b}}{\sqrt{a+b}+\sqrt{a+b}}+\frac{a-b}{\sqrt{a^2-b^2}-a+b}\))\(\frac{a^2+b^2}{\sqrt{a^2-b^2}}\)
e. E=\(\frac{\left(\sqrt{a}-\sqrt{b}\right)+4\sqrt{ab}}{\sqrt{a}+\sqrt{b}}-\frac{a\sqrt{b}-b\sqrt{a}}{\sqrt{ab}}-b\)
Cho bt:
\(Q=\frac{\sqrt{x-\sqrt{4x-1}}+\sqrt{x+\sqrt{4x-1}}}{\sqrt{x^2-4x-1}}.\left(1-\frac{1}{x-1}\right)\)
a. Tìm Dkxd
b. Rút gọn
Tìm x :
h/ \(\sqrt{x+5}-10=-4\)
i/ \(\sqrt{x-5}+2\sqrt{4x-20}-\frac{1}{3}\sqrt{9x-45}=12\)
j/ \(3\sqrt{2x}+\frac{1}{7}\sqrt{98x}-\sqrt{72x}+4=0\)
k/ \(\sqrt{4x^2-20}-\frac{1}{3}\sqrt{x^2-5}+\sqrt{\frac{9x^2-45}{16}}-\frac{1}{2}\sqrt{\frac{25x^2-125}{36}}=4\)
l/ \(\sqrt{4x+4}+\sqrt{9x+9}-\sqrt{x+1}=4\)
m/ \(\sqrt{16\left(x+1\right)}+\sqrt{4x+4}=16-\sqrt{x+1}+\sqrt{9x+9}\)
Giúp mk với nhé mn
Cho biểu thức : \(A=\left(\frac{\sqrt{x}-4x}{1-4x}-1\right):\left(\frac{1+2x}{1-4x}-\frac{2\sqrt{x}}{2\sqrt{x}-1}-1\right)\) .
a, Rút gọn A
b, Tìm x để \(A>A^2\)
Tìm giá trị nhỏ nhất của biểu thức
A=\(\frac{4x^2+9x+18\sqrt{x}+9}{4x\sqrt{x}+4x}+\frac{4x\sqrt{x}+4x}{4x^2+9x+18\sqrt{x}+9}\)
Cho x,y thỏa mãn x>1, y<0 và \(\frac{\left(x+y\right)\left(x^3-y^3\right)\sqrt{4x-2\sqrt{4x-1}}}{\left(1-\sqrt{4x-1}\right)\left(x^2y^2+xy^3+y^4\right)}=-8\). Vậy \(\frac{x}{y}=\)
Bài 2 :
U = \(\frac{4x}{x^2+x\sqrt{x}+\sqrt{x}+1}:\left(\frac{1}{x+2\sqrt{x}+1}-\frac{2}{1-x}+\frac{1}{x-2\sqrt{x}+1}\right)\)
a, Tìm đkxđ
b, Rút gọn
Bài 1 : Rút gọn biểu thức
a,\(\sqrt{\frac{\left(x-2\right)^4}{\left(3-x\right)^2}+\frac{x^2-1}{x-3}}\) ( x < 3 )
b,\(4x-\sqrt{8}+\frac{\sqrt{x^3+2x^2}}{\sqrt{x+2}}\) (x >-2)
c,\(\left|x-2\right|+\frac{\sqrt{x^2-4x+4}}{2}\)( x > 2)
Help me !!!
