ĐKXĐ: ...
\(\Leftrightarrow\sqrt{2-2x}+2\sqrt{2x+3}=8x^2-8x+7\)
Áp dụng BĐT Bunhiacopxki:
\(VT=\sqrt{2-2x}+2\sqrt{2x+3}\le\sqrt{\left(1+2^2\right)\left(2-2x+2x+3\right)}=5\)
\(VP=8x^2-8x+7=2\left(2x-1\right)^2+5\ge5\ge VT\)
Dấu "=" xảy ra khi và chỉ khi:
\(\left\{{}\begin{matrix}4\left(2-2x\right)=2x+3\\2x-1=0\end{matrix}\right.\) \(\Rightarrow x=\frac{1}{2}\)
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, \(\frac{2x^2+8x+1}{2x+1}=5\sqrt{x}\)
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) \(\sqrt{\frac{2x-1}{x}}+1+\sqrt{\frac{x}{2x-1}}=\frac{3x}{2x-1}\)
Giải các phương trình sau:
a)\(\frac{2x-5}{2x^2+3x-5}+\frac{3x+1}{1-x}=\frac{x+20}{4x+10}\)
b)\(\sqrt{5x+1}=\sqrt{14x+7}+\sqrt{2x+3}\)
c)\(\sqrt{x+3}-\sqrt{x+1}=\sqrt{5x+7}\)
d)\(\sqrt{\left(x-3\right)^2\left(x-1\right)}=x-3\)
e)\(\sqrt{x^2+2x+2}=1-x\)
f)\(\sqrt{x^4+x^2+4}=x^2+2\)
g)\(2x^2-6x+1=\sqrt{4x+5}\)
h)\(x^2+\sqrt{x+11}=11\)
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 phương trình: \(3x^2+4x^2-6=2\left(x^2+2x-\frac{2}{x}\right)\sqrt{x^3+x^2-2}\) giải luôn giúp e với ạ
giải pt
a) \(\sqrt{2x+3}+\sqrt{4-x}=6x-3\left(\sqrt{2x+3}-\sqrt{4-x}\right)^2-10\)
b) \(\sqrt{4x+1}+2\sqrt{1-x}+10\sqrt{-4x^2+3x+1}=13\)
c) \(\left(x^2+1\right)^2=13-x\sqrt{2x^2+4}\)
d) \(\left(\sqrt{x+1}+\sqrt{x-1}\right)^2-3=\frac{1}{\sqrt{x+1}-\sqrt{x-1}}\)
e) \(\left(\frac{2x-3}{\sqrt{x^2-1}}+2\right)\left(\frac{1}{\sqrt{x-1}}-\frac{1}{\sqrt{x+1}}\right)=\frac{1}{x^2-1}\)
giải phương trình
\(\frac{2x}{\sqrt{x^2+1}}=\frac{x^2+2}{4x^2+1}\)
Giải phương trình:
1) \(3x^2+4x-3=4x\sqrt{4x-3}\)
2) \(\sqrt{x^2+2x}+\sqrt{x+2}=\sqrt{x}+\sqrt{x^2+2x-2}\)
3) \(\sqrt{3x+8}-\sqrt{3x+5}=\sqrt{5x-4}-\sqrt{5x-7}\)
4) \(\sqrt{7-x^2+x\sqrt{x+5}}=\sqrt{3-2x-x^2}\)
