a. cho phương trình \(x^2-3\left(m-1\right)x-m^2-15=0\) . Tìm m để phương trình có 2 nghiệm phân biệt \(x_1\),\(x_2\) sao cho \(2x_1-x_2=-12\)
b. cho phương trình \(x^2-\left(m+2\right)x+m^2+1=0\). Tìm m để phương trình có 2 nghiệm phân biệt \(x_1\), \(x_2\) sao cho\(x^2_1\)+\(2x_2^2=3x_1x_2\)
a. \(\sqrt{1-2x}=x+7\)
b.\(\sqrt{1+x^2}=2x-1\)
c.\(\sqrt{1-x}-\sqrt{2+x}=1\)
d. \(\sqrt{1-x}+\sqrt{4+x}=3\)
e. \(\left|2x+5\right|\)= x-1
f. \(\left|x\right|+\left|2x-1\right|=x+2\)
g.\(\left|x-9\right|^{10}+\left|x-10\right|^{10}=1\)
h. \(\left|x-2014\right|^{2015}+\left|x-2015\right|^{2014}=1\)
i. \(\sqrt{x+3+4\sqrt{x-1}}+\sqrt{x+8-6\sqrt{x-1}}=5\)
k. \(\sqrt{x+2\sqrt{x-1}}+\sqrt{x-2\sqrt{x-1}}=x-1\)
l. \(\sqrt{x+2-4\sqrt{x-2}}+\sqrt{x+7-6\sqrt{x-2}}=1\)
m. \(\sqrt{x+8+2\sqrt{x+7}}+\sqrt{x-1-2\sqrt{x+7}}=4\)
m. \(x+\sqrt{x+\frac{1}{4}+\sqrt{x+\frac{1}{4}}}=\frac{9}{4}\)
n.\(\left(x+5\right)^4+\left(x+7\right)^4=2\)
Giải pt
a. \(\left\{{}\begin{matrix}x^2-3x+2y=2\\2x^2+y-x=3\end{matrix}\right.\)
b.\(\left\{{}\begin{matrix}x^2+y^2+xy-3y=4\\2x-3y+xy=3\end{matrix}\right.\)
c.\(\left\{{}\begin{matrix}2x^2=y+\frac{1}{y}\\2y^2=x+\frac{1}{x}\end{matrix}\right.\)
d.\(\left\{{}\begin{matrix}x^2-2y^2-xy-2x+7y-3=0\\x^2+y^2-x+y=0\end{matrix}\right.\)
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=\(\frac{\left(\sqrt{a}-\sqrt{b}\right)+4\sqrt{ab}}{\sqrt{a}+\sqrt{b}}-\frac{a\sqrt{b}-b\sqrt{a}}{\sqrt{ab}}-b\)