giair phương trình \(\sqrt{x}+\sqrt{1-}+\sqrt{x\left(1-x\right)}=1\)
Giair phương trình:
1) \(\sqrt[5]{32-x^2}-\sqrt[5]{1-x^2}=4\)
2) \(\sqrt{x}+\sqrt[4]{20-x}=4\)
3) \(x^3+1=2\sqrt{3x-1}\)
4) \(\sqrt[3]{x-1}+3=\sqrt[4]{82-x}\)
5)
\(a.\left(x+3\sqrt{x}+2\right)\left(x+9\sqrt{x}+18\right)=168x\)
\(b.\sqrt{5x^2+14x+9}-\sqrt{x^2-x-20}=5\sqrt{x+1}\)
a) ĐKXĐ: \(x\ge0\)
Ta có: \(\left(x+3\sqrt{x}+2\right)\left(x+9\sqrt{x}+18\right)=168x\)
\(\Leftrightarrow\left(\sqrt{x}+1\right)\left(\sqrt{x}+2\right)\left(\sqrt{x}+3\right)\left(\sqrt{x}+6\right)=168x\)
\(\Leftrightarrow\left(x+6\right)^2+12\sqrt{x}\left(x+6\right)-133=0\)
\(\Leftrightarrow\left(x+6\right)^2+19\sqrt{x}\left(x+6\right)-7\sqrt{x}\left(x+6\right)-133=0\)
\(\Leftrightarrow\left(x+6\right)\left(x+19\sqrt{x}+6\right)-7\sqrt{x}\left(x+19\sqrt{x}+6\right)=0\)
\(\Leftrightarrow\left(x-7\sqrt{x}+6\right)=0\)
\(\Leftrightarrow\left(\sqrt{x}-1\right)\left(\sqrt{x}-6\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=36\end{matrix}\right.\)
Giair phương trình: \(\left(x+2\right)\sqrt{3x+6}-2\sqrt{x^2+x-1}+3x^2-10=0\)
giair phương trình:
\(\sqrt{x-1}\)+ \(\sqrt{4-x}\)+ \(\sqrt{\left(x-1\right)\left(4-x\right)}\)=5
Điều kiện \(1\le x\le4\)
Đặt \(\hept{\begin{cases}\sqrt{x-1}=a\\\sqrt{4-x}=b\end{cases}}\)
Ta có \(\hept{\begin{cases}a+b+ab=5\\a^2+b^2=3\end{cases}}\)
=> PT vô nghiệm
Giair phương trình
\(\frac{1}{\sqrt{x}}+\frac{1}{\sqrt{x}+1}=\sqrt{5}.\left(\frac{1}{\sqrt{6x-1}}+\frac{1}{\sqrt{9x-4}}\right).\)
có làm thì mới có ăn, không làm mà đòi có ăn chịu khó ăn ***, ăn đầu ****
Giair phương trình: \(\left(2\sqrt{x+2}-\sqrt{4x-1}\right)\left(2x+3+\sqrt{4x^2}+9x+2\right)=7\)
Giair phương trình sau:
a,\(\left(x-\sqrt{2}\right)+3\left(x^2-2\right)=0\)
b,\(x^2-5=\left(2x-\sqrt{5}\right)\left(x+\sqrt{5}\right)\)
a) Ta có: \(\left(x-\sqrt{2}\right)+3\left(x^2-2\right)=0\)
\(\Leftrightarrow\left(x-\sqrt{2}\right)+3\left(x-\sqrt{2}\right)\left(x+\sqrt{2}\right)=0\)
\(\Leftrightarrow\left(x-\sqrt{2}\right)\left(1+3x+3\sqrt{2}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-\sqrt{2}=0\\3x+3\sqrt{2}+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\sqrt{2}\\3x=-3\sqrt{2}-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\sqrt{2}\\x=\dfrac{-3\sqrt{2}-1}{3}\end{matrix}\right.\)
Vậy: \(S=\left\{\sqrt{2};\dfrac{-3\sqrt{2}-1}{3}\right\}\)
b) Ta có: \(x^2-5=\left(2x-\sqrt{5}\right)\left(x+\sqrt{5}\right)\)
\(\Leftrightarrow\left(x+\sqrt{5}\right)\left(x-\sqrt{5}\right)-\left(2x-\sqrt{5}\right)\left(x+\sqrt{5}\right)=0\)
\(\Leftrightarrow\left(x+\sqrt{5}\right)\left(x-\sqrt{5}-2x+\sqrt{5}\right)=0\)
\(\Leftrightarrow-x\left(x+\sqrt{5}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}-x=0\\x+\sqrt{5}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-\sqrt{5}\end{matrix}\right.\)
Vậy: \(S=\left\{0;-\sqrt{5}\right\}\)
Giair phương trình \(x^2+3x+1=\left(x+3\right)\sqrt{x^2+1}\)
Đặt \(\sqrt{x^2+1}=a\left(a>0\right),x+3=b\)
\(Pt\Leftrightarrow a^2+3b-9=ab\)
\(\Leftrightarrow\left(a-3\right)\left(a+3\right)-b\left(a-3\right)=0\)
\(\Leftrightarrow\left(a-3\right)\left(a+3-b\right)=0\Leftrightarrow\orbr{\begin{cases}a=3\\a+3=b\end{cases}}\left(tm\right)\)
* \(a=3\Leftrightarrow\sqrt{x^2+1}=3\Leftrightarrow x^2+1=9\Leftrightarrow x^2=8\Leftrightarrow\orbr{\begin{cases}x=2\sqrt{2}\\x=-2\sqrt{2}\end{cases}}\)
*\(a+3=b\Leftrightarrow\sqrt{x^2+1}+3=x+3\)( bình phương tiếp với x>-3)( hình như k có nghiệm)
Giair phương trình:
\(\left(x^2+6x+10\right)^2+\left(x+3\right)\left(3x^2+20x+36\right)\)=0\(\frac{4x+2}{\sqrt{x+3}}+x\sqrt{x+8}=\)\(x\left(2x+1\right)+2\sqrt{\frac{x+8}{x+3}}\)Giair phương trình sau :
\(5+x=2\sqrt{\left(4-x\right)\left(2x-2\right)}=4\left(\sqrt{4-x}+\sqrt{2x-2}\right)\)