Giai phuong trinh \(\sqrt{2x^2+8x+6}+\sqrt{x^2-1}=2x+2\)
giai phuong trinh: \(\sqrt{2x^2-1}+\sqrt{x^2-3x-2}=\sqrt{2x^2+2x+3}+\sqrt{x^2-x-1}\)
giai phuong trinh \(\sqrt{2x+4-6\sqrt{2x-5}}+\sqrt{2x-4+2\sqrt{2x-5}}=4\)
\(\sqrt{2x+4-6\sqrt{2x-5}}+\sqrt{2x-4+2\sqrt{2x-5}}=4\)
\(\Leftrightarrow\sqrt{2x-5-6\sqrt{2x-5}+9}+\sqrt{2x-5+2\sqrt{2x-5}+1}=4\)
\(\Leftrightarrow\sqrt{\left(\sqrt{2x-5}-3\right)^2}+\sqrt{\left(\sqrt{2x-5}+1\right)^2}=4\)
\(\Leftrightarrow\left|\sqrt{2x-5}-3\right|+\left|\sqrt{2x-5}+1\right|=4\)
\(\Leftrightarrow\orbr{\begin{cases}\sqrt{2x-5}-3+\sqrt{2x-5}+1=4\\\sqrt{2x-5}-3+\sqrt{2x-5}+1=-4\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}2\sqrt{2x-5}-2=4\\2\sqrt{2x-5}-2=-4\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}2\sqrt{2x-5}=6\\2\sqrt{2x-5}=-2\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}\sqrt{2x-5}=3\\\sqrt{2x-5}=-1\left(L\right)\end{cases}}\)
\(\Leftrightarrow2x-5=9\)
\(\Leftrightarrow x=7\)
Giai phuong trinh
\(\sqrt{x+2+3\sqrt{2x-5}}+\sqrt{x-2-2\sqrt{2x-5}}=2\sqrt{2}\)
Giai phuong trinh ; 2\(\sqrt{x^2-x}-2\sqrt{x}\sqrt{2x-1}+3x=1\)
giai phuong trinh \(\sqrt{\frac{x+7}{x+1}}+8=2x^2+\sqrt{2x-1}\)
ĐKXĐ: \(x\ge\frac{1}{2}\)
Đề \(\Rightarrow\sqrt{\frac{x+7}{x+1}}-\sqrt{3}+8-2x^2-\left(\sqrt{2x-1}-\sqrt{3}\right)=0\)
Nhân liên hợp ta được:
\(\frac{\left(\sqrt{\frac{x+7}{x+1}}-\sqrt{3}\right)\left(\sqrt{\frac{x+7}{x+1}}+\sqrt{3}\right)}{\sqrt{\frac{x+7}{x+1}}+\sqrt{3}}+2\left(4-x^2\right)-\frac{\left(\sqrt{2x-1}-\sqrt{3}\right)\left(\sqrt{2x+1}+\sqrt{3}\right)}{\sqrt{2x+1}+\sqrt{3}}=0\)
\(\Rightarrow\frac{\frac{x+7}{x+1}-3}{\sqrt{\frac{x+7}{x+1}}+\sqrt{3}}+2\left(4-x^2\right)-\frac{2x-1-3}{\sqrt{2x+1}+\sqrt{3}}=0\)
\(\Rightarrow\frac{\frac{-2x+4}{x+1}}{\sqrt{\frac{x+7}{x+1}}+\sqrt{3}}+2\left(2-x\right)\left(2+x\right)-\frac{2x-4}{\sqrt{2x+1}+\sqrt{3}}=0\)
\(\Rightarrow\left(x-2\right)\left[\frac{-2}{\left(x+1\right)\left(\sqrt{\frac{x+7}{x+1}}+\sqrt{3}\right)}-2\left(2+x\right)-\frac{2}{\sqrt{2x+1}+\sqrt{3}}\right]=0\)
mà \(-\frac{2}{\left(x+1\right)\left(\sqrt{\frac{x+7}{x+1}}+\sqrt{3}\right)}-2\left(2+x\right)-\frac{2}{\sqrt{2x+1}+\sqrt{3}}< 0\)
=> x - 2 = 0 => x = 2
Vậy x = 2
Giai phuong trinh :\(\sqrt{2-x^2+2x}+\sqrt{-x^2-6x+8}=1+\sqrt{3}\)
Giai phuong trinh:
\(\sqrt{x^2+2x-2}+2\sqrt{x^2+2x-2}=x+2\)
Bình phương hai vế lên ta được:
x2+2x-2+4(x2+2x-2)=(x+2)2
<=>x2+2x-2+4x2+8x-8=x2+4x+4
<=>x2+4x2-x2+2x+8x-4x-2-8-4=0
<=>4x2+6x-14=0
<=>2x2+3x-7=0
Đến đây bạn tự làm tiếp nha. Nhớ k cho mk đấy
Giai phuong trinh:
\(\sqrt{x^2+2x-2}+2\sqrt{x^2+2x-2}=x+2\)
\(\sqrt{x^2-2x+1}=2x\)
giai phuong trinh
\(\sqrt{x^2-2x+1}=2x\)
\(\Leftrightarrow\)\(\sqrt{\left(x-1\right)^2}=2x\)
\(\Leftrightarrow\)\(\left|x-1\right|=2x\)
+) Với \(x-1\ge0\)\(\Leftrightarrow\)\(x\ge1\) ta có :
\(x-1=2x\)
\(\Leftrightarrow\)\(x=-1\) ( không thỏa mãn )
+) Với \(x-1< 0\)\(\Leftrightarrow\)\(x< 1\) ta có :
\(1-x=2x\)
\(\Leftrightarrow\)\(x=\frac{1}{3}\) ( thỏa mãn )
Vậy \(x=\frac{1}{3}\)
Chúc bạn học tốt ~
Bình phương 2 vế
\(x^2-2x+1=4x^2\)
\(\left(x-1\right)^2-\left(2x\right)^2=0\)
\(\left(x-1-2x\right)\left(x-1+2x\right)=0\)
\(\left(-x-1\right)\left(3x-1\right)=0\)
\(\Rightarrow\orbr{\begin{cases}-x-1=0\\3x-1=0\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=-1\\x=\frac{1}{3}\end{cases}}\)