tìm x biết
a ) \(x^2+4x=23-10\sqrt{2}\)
b)\(\left(2x-1\right)^2=\left|1-2x\right|\)
c) \(\left(x-2\right)^2+\left(2x+1\right)^2=0\)
Tìm x để biểu thức sau xác định:
a) \(\sqrt{\left(x+2\right).\left(x-1\right)}\)
b) \(\sqrt{\dfrac{x-3}{2x-1}}\)
c) \(\sqrt{-x^2+2x-1^{ }}\)
Chứng minh \(\left(3x+3y\right)\left(\frac{1}{x+2y}+\frac{1}{2x+y}\right)\ge4\) trong đó x > 0 và y > 0
Giải hpt:
\(\left\{{}\begin{matrix}x^2+y^2+xy+1=4y\\y\left(x+y\right)^2=2x^2+7y+2\end{matrix}\right.\)
Bt : Rút gọn
a) \(\sqrt{\left(x-3\right)^2}\)
b) \(\sqrt{\left(3x+1\right)^2}+2x\) vs( x<1/3)
c) \(\sqrt{\left(1-2x\right)^2}+2x\) vs ( x>hoặc = 1/2 )
a:\(\dfrac{b}{\left(a-4\right)^2}.\sqrt{\dfrac{\left(a-4\right)^4}{b^2}}\left(b>0;a\ne4\right)\)
b:\(\dfrac{x\sqrt{x}-y\sqrt{y}}{\sqrt{x}-\sqrt{y}}\left(x\ge0;y\ge0;x\ne0\right)\)
c:\(\dfrac{a}{\left(b-2\right)^2}.\sqrt{\dfrac{\left(b-2\right)^4}{a^2}\left(a>0;b\ne2\right)}\)
d:\(\dfrac{x}{\left(y-3\right)^2}.\sqrt{\dfrac{\left(y-3\right)^2}{x^2}\left(x>0;y\ne3\right)}\)
e:2x +\(\dfrac{\sqrt{1-6x+9x^2}}{3x-1}\)
\(\sqrt{x-1}+\sqrt{x}+3+2\sqrt{\left(x-1\left(x+3\right)\right)}=4-2x\)
\(\sqrt{x+3}+\sqrt{x+1}+2\sqrt{\left(x+3\right)\left(x+1\right)}=4-2x\)
1: rút gọn \(A=\dfrac{2}{x^2-1}-\dfrac{1}{x^2+x}+\dfrac{x^2-3}{x^3-x}\); \(B=\dfrac{2}{x-1}+\dfrac{2x-1}{x^2+x+1}+\dfrac{x^2+6x+2}{x^3-1}\)
2: tìm x: \(\dfrac{4}{3}\left(x-2\right)+\dfrac{\left(x-1\right)\left(x+2\right)}{2}=3-\dfrac{5x\left(1-2x\right)}{4}\)