giải phuơng trình
\(\left(\sqrt{1+x}-1\right)\left(\sqrt{1-x}+1\right)=3x\)
giải phương trình :
a, \(\left(\sqrt{5x-1}+\sqrt{x-1}\right)\left(3x-1-\sqrt{5x^2-6x+1}\right)=4x\)
b, \(2\left(\sqrt{x}-\sqrt{x-1}\right)\left(1+\sqrt{x^2-1}\right)=x\sqrt{x}\)
giải phương trình :
a, \(\left(\sqrt{5x-1}+\sqrt{x-1}\right)\left(3x-1-\sqrt{5x^2}-6x+1\right)=4x\)
b, \(2\left(\sqrt{x}-\sqrt{x-1}\right)\left(1+\sqrt{x^2-1}\right)=x\sqrt{x}\)
Giải phương trình:
\(\sqrt{x\left(3x+1\right)}-\sqrt{x\left(x-1\right)}=2\left|x\right|\)
Giải phương trình:
\(\frac{2\left(x-\sqrt{3}\right)\left(x-\sqrt{2}\right)}{\left(1-\sqrt{2}\right)\left(1-\sqrt{3}\right)}+\frac{3\left(x-1\right)\left(x-\sqrt{3}\right)}{\left(\sqrt{2}-1\right)\left(\sqrt{2}-\sqrt{3}\right)}+\frac{4\left(x-1\right)\left(x-\sqrt{2}\right)}{\left(\sqrt{3}-1\right)\left(\sqrt{3}-\sqrt{2}\right)}=3x-1\)
Giải phương trình sau
1. \(5x^2-16x+7+\left(x+1\right)\sqrt{x^2+3x-1}=0\)
2. \(3\left(\sqrt{2x^2+1}-1\right)=x\left(1+3x+8\sqrt{2x^2+1}\right)\)
\(\left(\frac{2x-1}{2-x}+2\sqrt{2-x}\right)^3=27\left(2x-1\right)\)
Giải phương trình nghiệm nguyên sau:
\(3x^3-13x^2+30x-4=\sqrt{\left(6x+2\right)\left(3x-4\right)^3}\)
Bài Toán :
Giải phương trình sau :
\(\frac{3\left(x-\sqrt{3}\right)\left(x-\sqrt{5}\right)}{\left(1-\sqrt{3}\right)\left(1-\sqrt{5}\right)}+\frac{4.\left(x-1\right)\left(x-\sqrt{5}\right)}{\left(\sqrt{3}-1\right)\left(\sqrt{3}-\sqrt{5}\right)}+\frac{5\left(x-1\right)\left(x-\sqrt{3}\right)}{\left(\sqrt{5}-1\right)\left(\sqrt{5}-\sqrt{3}\right)}=3x-2\)
Giải phương trình sau: \(\left(x+1\right)\left(\sqrt{x^2+3}+\sqrt{3x^2+1}\right)=2\sqrt{\left(x^2+3\right)\left(3x^2+1\right)}\)
Giải hệ phương trình:
\(\left\{{}\begin{matrix}y^3-4y^2+4y=\sqrt{x+1}\left(y^2-5y+4+\sqrt{x+1}\right)\\2\sqrt{x^2-3x+3}+6x-7=y^2\left(x-1\right)^2+\left(y^2-1\right)\sqrt{3x-2}\end{matrix}\right.\)
ĐKXĐ: ...
\(y\left(y^2-5y+4\right)+y^2=\left(y^2-5y+4\right)\sqrt{x+1}+x+1\)
\(\Leftrightarrow\left(y^2-5y+4\right)\left(y-\sqrt{x+1}\right)+\left(y+\sqrt{x+1}\right)\left(y-\sqrt{x+1}\right)=0\)
\(\Leftrightarrow\left(y-\sqrt{x+1}\right)\left[\left(y-2\right)^2+\sqrt{x+1}\right]=0\)
\(\Leftrightarrow y=\sqrt{x+1}\Rightarrow y^2=x+1\)
Thế xuống pt dưới:
\(2\sqrt{x^2-3x+3}+6x-7=\left(x+1\right)\left(x-1\right)^2+x\sqrt{3x-2}\)
\(\Leftrightarrow2\left(\sqrt{x^2-3x+3}-1\right)+x\left(x-\sqrt{3x-2}\right)=x^3-7x+6\)
\(\Leftrightarrow\dfrac{2\left(x^2-3x+2\right)}{\sqrt{x^2-3x+3}+1}+\dfrac{x\left(x^2-3x+2\right)}{x+\sqrt{3x-2}}=\left(x+3\right)\left(x^2-3x+2\right)\)
\(\Leftrightarrow\left[{}\begin{matrix}x^2-3x+2=0\\\dfrac{2}{\sqrt{x^2-3x+3}+1}+\dfrac{x}{x+\sqrt{3x-2}}=x+3\left(1\right)\end{matrix}\right.\)
Xét (1) với \(x\ge\dfrac{3}{2}\):
\(\dfrac{2}{\sqrt{x^2-3x+3}+1}\le8-4\sqrt{3}< 1\)
\(\sqrt{3x-2}\ge0\Rightarrow\dfrac{x}{x+\sqrt{3x-2}}\le1\)
\(\Rightarrow\left\{{}\begin{matrix}\dfrac{2}{\sqrt{x^2-3x+3}+1}+\dfrac{x}{x+\sqrt{3x-2}}< 2\\x+3>2\end{matrix}\right.\)
\(\Rightarrow\left(1\right)\) vô nghiệm
Giải hệ bất phuơng trình:
\(\left\{{}\begin{matrix}\dfrac{1}{\sqrt{x}}+\dfrac{y}{x}=\dfrac{2\sqrt{x}}{y}+2\\y\left(\sqrt{x^2+1}-1\right)=\sqrt{3x^2+3}\end{matrix}\right.\)
ĐKXD: x, y > 0.
\(Pt_{\left(1\right)}\Leftrightarrow\dfrac{y+\sqrt{x}}{x}=\dfrac{2\left(y+\sqrt{x}\right)}{y}\Leftrightarrow\left(y+\sqrt{x}\right)\left(\dfrac{1}{x}-\dfrac{2}{y}\right)=0\)
\(\Rightarrow y=2x\), thế vào Pt(2): \(2x\left(\sqrt{x^2+1}-1\right)=\sqrt{3x^2+3}\)
Đặt \(\sqrt{x^2+1}=a\) thì \(\left\{{}\begin{matrix}2x\left(a-1\right)=\sqrt{3}a\\a^2-x^2=1\end{matrix}\right.\)
Giải ra ta được \(\left(a-2\right)\left(4a^3-3a+2\right)=0\) nhưng vì \(a\ge1\) nên a=2
Do đó \(x=\pm\sqrt{3}\). Vậy (x, y)=...