Đặt \(\sqrt{2x^2-8x+12}=t>0\Rightarrow x^2-4x=\frac{t^2-12}{2}\)
\(\frac{t^2-12}{2}-6=2t\)
\(\Leftrightarrow t^2-4t-24=0\Rightarrow\left[{}\begin{matrix}t=2+2\sqrt{7}\\t=2-2\sqrt{7}\left(l\right)\end{matrix}\right.\)
\(\Rightarrow\sqrt{2x^2-8x+12}=2+2\sqrt{7}\)
\(\Leftrightarrow x^2-4x+5-\sqrt{7}=0\)
Nghiệm pt này bạn tự tính tay, làm biếng quá
Giải phương trình:
1. \(x^4-6x^2-12x-8=0\)
2. \(\dfrac{x}{2x^2+4x+1}+\dfrac{x}{2x^2-4x+1}=\dfrac{3}{5}\)
3. \(x^4-x^3-8x^2+9x-9+\left(x^2-x+1\right)\sqrt{x+9}=0\)
4. \(2x^2.\sqrt{-4x^4+4x^2+3}=4x^4+1\)
5. \(x^2+4x+3=\sqrt{\dfrac{x}{8}+\dfrac{1}{2}}\)
6. \(\left\{{}\begin{matrix}4x^3+xy^2=3x-y\\4xy+y^2=2\end{matrix}\right.\)
7. \(\left\{{}\begin{matrix}\sqrt{x^2-3y}\left(2x+y+1\right)+2x+y-5=0\\5x^2+y^2+4xy-3y-5=0\end{matrix}\right.\)
8. \(\left\{{}\begin{matrix}\sqrt{2x^2+2}+\left(x^2+1\right)^2+2y-10=0\\\left(x^2+1\right)^2+x^2y\left(y-4\right)=0\end{matrix}\right.\)
giải pt
a) \(3\sqrt{x}+\frac{3}{2\sqrt{x}}=2x+\frac{1}{2x}-7\)
b) \(5\sqrt{x}+\frac{5}{2\sqrt{x}}=2x+\frac{1}{2x}+4\)
c) \(\sqrt{2x^2+8x+5}+\sqrt{2x^2-4x+5}=6\sqrt{x}\)
d) \(x+1+\sqrt{x^2-4x+1}=3\sqrt{x}\)
e) \(x^2+2x\sqrt{x-\frac{1}{x}}=3x+1\)
f) \(x^2-6x+x\sqrt{\frac{x^2-6}{x}}-6=0\)
g) \(\frac{3x^2}{3+\sqrt{x}}+6+2\sqrt{x}=5x\)
h) \(\frac{x^2}{4-3\sqrt{x}}+8=3\left(x+2\sqrt{x}\right)\)
Giải pt
a) \(2x^2+\sqrt{x^2-5x-6}=10x+15\)
b) \(5\sqrt{3x^2-4x-2}-6x^2+8x+7=0\)
c) \(x^2+\sqrt{2x^2+4x+3}=6-2x\)
d) \(2\sqrt{\frac{3x-1}{x}}=\frac{x}{3x-1}+1\)
e) \(\sqrt{\frac{24x-4}{x}}=\frac{x}{6x-1}+1\)
f) \(\sqrt{\frac{2x-1}{x}}+1+\sqrt{\frac{x}{2x-1}}=\frac{3x}{2x-1}\)
ai giúp t với
1:\(\left\{\begin{matrix}x\sqrt{12-y}+\sqrt{y\left(12-x^2\right)}=12\\x^3-8x-1=2\sqrt{y-2}\end{matrix}\right.\)
2:\(\left\{\begin{matrix}\left(1-y\right)\sqrt{x-y}+x=2+\left(x-y-1\right)\sqrt{y}\\2y^2-3x+6y+1=2\sqrt{x-2y}-\sqrt{4x-5y-3}\end{matrix}\right.\)
3:\(\left\{\begin{matrix}y\left(x^2+2x+2\right)=x\left(y^2+6\right)\\\left(y-1\right)\left(x^2+2x+7\right)=\left(x+1\right)\left(y^2+1\right)\end{matrix}\right.\)
4:\(\left\{\begin{matrix}x-2\sqrt{y+1}=3\\x^3-4x^2\sqrt{y+1}-9x-8y=-52-4xy\end{matrix}\right.\)
5:\(\left\{\begin{matrix}\frac{y-2x+\sqrt{y}-x}{\sqrt{xy}}+1=0\\\sqrt{1-xy}+x^2-y^2=0\end{matrix}\right.\)
\(\sqrt{x+2}+\sqrt{5x+6}+2\sqrt{8x+9}=4x^2\)
giải pt
a) \(x\sqrt{x^2-4x+3}=x^2+x\)
b) \(x^2+x-12-\left(x-3\right)\sqrt{10-x^2}=0\)
c) \(\sqrt{6+x-x^2}=\frac{\left(2x+5\right)\sqrt{6+x-x^2}}{x+4}\)
d) \(\sqrt{\frac{12+x-x^2}{2x+9}}-\frac{\sqrt{12+x-x^2}}{x+3}=0\)
e) \(\sqrt{x^3}+\sqrt{x^3+x^2+2x}=3\sqrt{x}\)
\(a,2x^2-9x+3+\sqrt{3x^2-7x+1}=0\)
b)\(\sqrt{x+2}+\sqrt{3-x}=x^3+x^2-4x-1\)
c)\(\text{4x^3-9x^2+7x-(3x-1)\sqrt{3x-2}=0}\)
d)\(2\sqrt{x-1}+\sqrt{5x-1}=x^2+1\)
e)\(\sqrt{x+2}+\sqrt{5x+6}+2\sqrt{8x+9}=4x^2\)
f)\(3x^2-x+3=\sqrt{3x+1}+\sqrt{5x+4}\)
Giải phương trình:
a) \(\sqrt{x+2}=\sqrt{2x+1}+x\sqrt{x+2}\)
b) \(2+\sqrt{3-8x}=6x+\sqrt{4x-1}\)
c) \(\sqrt{10x+1}+\sqrt{3x-5}=\sqrt{9x+4}+\sqrt{2x-1}\)
d) \(1+\sqrt{x^2+4x}=\sqrt{x^2-3x+3}+\sqrt{2x^2+x+2}\)
e) \(\sqrt{x^2+15}=3x-2+\sqrt{x^2+8}\)
f) \(\left(\sqrt{x+5}-\sqrt{x+2}\right)\left(1+\sqrt{x^2+7x+10}\right)=3\)
g) \(\sqrt{3x^2-7x+3}-\sqrt{x^2-2}=\sqrt{3x^2-5x-1}-\sqrt{x^2-3x+4}\)
h) \(\sqrt{2x^2+x-1}+\sqrt{3x^2+x-1}=\sqrt{x^2+4x-3}+\sqrt{2x^2+4x-3}\)
Giải các phương trình sau:
a, \(\sqrt{4x-1}+4x^2-6x+1=0\)
b, \(\sqrt{3x^2-2x+9}+\sqrt{3x^2-2x+2}=7\)
c,\(3\sqrt{x}+8=9x+\frac{1}{x}+\frac{1}{\sqrt{x}}\)
d, \(\frac{2x^2+8x+1}{2x+1}=5\sqrt{x}\)
