\(\sqrt{x+2+3\sqrt{2x-5}}+\sqrt{x-2-\sqrt{2x-5}}\)
giai pt tren ho minh nha
giải pt ạ
\(\sqrt{x-2+\sqrt{2x-5}}+\sqrt{x+2+3\sqrt{2x-5}}=7\sqrt{2}\)
ĐKXĐ: \(x\ge\dfrac{5}{2}\)
\(\sqrt{2x-4+2\sqrt{2x-5}}+\sqrt{2x+4+6\sqrt{2x-5}}=14\)
\(\Leftrightarrow\sqrt{\left(\sqrt{2x-5}+1\right)^2}+\sqrt{\left(\sqrt{2x-5}+3\right)^2}=14\)
\(\Leftrightarrow\left|\sqrt{2x-5}+1\right|+\left|\sqrt{2x-3}+3\right|=14\)
\(\Leftrightarrow2\sqrt{2x-5}=10\)
\(\Leftrightarrow\sqrt{2x-5}=5\)
\(\Leftrightarrow2x-5=25\)
\(\Leftrightarrow x=15\)
Giai pt
\(\sqrt{x+5}=2\sqrt{x}-2\sqrt{2x-7}\)
Giai cac pt:
a, \(2x^2-8x+\sqrt{x^2-4x-5}=13\)
b, \(\sqrt{1-x}+\sqrt{4+x}=3\)
c, \(x^3+4x+5=2\sqrt{2x+3}\)
d, \(2\sqrt{2x+4}+4\sqrt{2-x}=\sqrt{9x^2-16}\)
e, \(\sqrt[3]{x-2}+\sqrt{x+1}=3\)
Giai pt
\(\left(\sqrt{2x+3}+2\right).\left(\sqrt{x+6}-\sqrt{x+1}\right)=5\)
\(\left(\sqrt{2x+3}+2\right)\left(\sqrt{x+6}-\sqrt{x+1}\right)=5\)
\(ĐKXĐ:x\ge-1\).Nhận thấy \(\sqrt{x+6}-\sqrt{x+1}>0\)
\(\Leftrightarrow\left(\sqrt{2x+3}+2\right)\frac{\left(\sqrt{x+6}+\sqrt{x+1}\right)\left(\sqrt{x+6}-\sqrt{x+1}\right)}{\sqrt{x+6}-\sqrt{x+1}}=5\)
\(\Leftrightarrow\left(\sqrt{2x+3}+2\right)\frac{5}{\sqrt{x+6}-\sqrt{x+1}}=5\)
\(\Leftrightarrow\frac{\sqrt{2x+3}+2}{\sqrt{x+6}-\sqrt{x+1}}=1\)
\(\Leftrightarrow\sqrt{2x+3}+2-\sqrt{x+6}+\sqrt{x+1}=0\)
Th1:\(\sqrt{x+1}=2\Leftrightarrow x=3\left(thoaman\right)\)
Th2:\(\sqrt{x+1}-2\ne0\Leftrightarrow x\ne3\)
\(\Leftrightarrow\left(\sqrt{2x+3}-\sqrt{x+6}\right)+\left(2+\sqrt{x+1}\right)=0\)
\(\Leftrightarrow\frac{x-3}{\sqrt{2x+3}+\sqrt{x+6}}+\frac{x-3}{\sqrt{x+1}-2}=0\)
\(\Leftrightarrow\left(x-3\right)\left(\frac{1}{\sqrt{2x+3}+\sqrt{x+6}}+\frac{1}{\sqrt{x+1}-2}\right)=0\)
Tự lm tiếp nha
Giai các PT sau
a, \(x=\sqrt{2-x}.\sqrt{3-x}+\sqrt{3-x}.\sqrt{5-x}+\sqrt{2-x}.\sqrt{5-x}\)
b, \(\sqrt{5x^2+14x+9}-\sqrt{x^2-x-20}=5\sqrt{x+1}\)
c, \(\sqrt{4x+1}+\sqrt{2x^2+x+39}=10\)
Giai các PT sau
a, \(x=\sqrt{2-x}.\sqrt{3-x}+\sqrt{3-x}.\sqrt{5-x}+\sqrt{2-x}.\sqrt{5-x}\)
b, \(\sqrt{5x^2+14x+9}-\sqrt{x^2-x-20}=5\sqrt{x+1}\)
c, \(\sqrt{4x+1}+\sqrt{2x^2+x+39}=10\)
giải pt :
a, (x+5)(2-x)=3\(\sqrt{x^2+3x}\)
b, \(\sqrt[3]{\dfrac{2x}{x+1}}+\sqrt[3]{\dfrac{1}{2}+\dfrac{1}{2x}}=2\)
c,\(\sqrt[5]{\dfrac{16x}{x-1}}+\sqrt[5]{\dfrac{x-1}{16x}}=\dfrac{5}{2}\)
d, \(\sqrt{5x^2+10x+1}=7-2x-x^2\)
e, \(\sqrt{2x^2+4x+1}=1-2x-x^2\)
giải pt \(\sqrt{x+2-3\sqrt{2x-5}}+\sqrt{x-2+\sqrt{2x-5}}=2\sqrt{2}\)
Hong Ra On chuyên gì thế hả sao gọi mình là sao
\(\sqrt{x+2-3\sqrt{2x-5}}+\sqrt{x-2+\sqrt{2x-5}}=2\sqrt{2}\)
\(\left\{{}\begin{matrix}x\ge\dfrac{5}{2};y=\sqrt{2x-5};y\ge0\\\sqrt{\dfrac{\left(y-3\right)^2}{2}}+\sqrt{\dfrac{\left(y+1\right)^2}{2}}=2\sqrt{2}\end{matrix}\right.\)
\(\left\{{}\begin{matrix}x\ge\dfrac{5}{2};y=\sqrt{2x-5};y\ge0\\\left|\dfrac{\left(y-3\right)}{\sqrt{2}}\right|+\left|\dfrac{\left(y+1\right)}{\sqrt{2}}\right|=\left|\dfrac{4}{\sqrt{2}}\right|=2\sqrt{2}=VP\end{matrix}\right.\)đẳng thức khi
\(7\ge x\ge\dfrac{5}{2}\)
kết luận
nghiệm của pt là : \(7\ge x\ge\dfrac{5}{2}\)
Cái căn thứ 2 hình như thiếu số 3 đúng không?
HD: nhân 2 vế vs \(\sqrt{2}\). Sau đó phân tích trong căn thành hằng đẳng thức
giai pt sau
\(\sqrt{3x-1}-\sqrt{x+2}.\sqrt{3x^2+7x+2}+4=4x-2\)
\(x^2-5x+3.\sqrt{2x-1}=2.\sqrt{14-2x}+5\)
\(\left(x+1\right)\left(x+4\right)-3\sqrt{x^2+5x+2}=6\)
nhiều thế giải ko đổi đâu bạn
đkxđ : \(\frac{1}{2}\le x\le7\)
\(x^2-5x+3\sqrt{2x-1}=2\sqrt{14-2x}+5\)
\(\Leftrightarrow\left(x^2-5x\right)+3\left(\sqrt{2x-1}-3\right)=2\left(\sqrt{14-2x}-2\right)\)
\(\Leftrightarrow x\left(x-5\right)+\frac{3.\left(2x-10\right)}{\sqrt{2x-1}+3}+\frac{2.\left(2x-10\right)}{\sqrt{14-2x}+2}=0\)
\(\Leftrightarrow\left(x-5\right)\left(x+\frac{6}{\sqrt{2x-1}+3}+\frac{4}{\sqrt{14-2x}+2}\right)=0\)
\(\Leftrightarrow x=5\)
còn bài a,c lười đánh lắm