\(\sqrt{x}+\sqrt{x+7}+2\sqrt{x^2+7x}=35-2x\)2x
\(\sqrt{7x^2+25x+19}-\sqrt{x^2+2x-35}=7\sqrt{x+2}\)
Giải pt
\(\sqrt{x}+\sqrt{x+7}+2\sqrt{x^2+7x}=35-2x\)
ĐK \(x\ge0\)
\(\Leftrightarrow\sqrt{x}+\sqrt{x+7}+x+2\sqrt{x\left(x+7\right)}+x+7=42\)
\(\Leftrightarrow\left(\sqrt{x}+\sqrt{x+7}\right)+\left(\sqrt{x}+\sqrt{x+7}\right)^2=42\)
\(\Leftrightarrow\left(\sqrt{x}+\sqrt{x+7}\right)^2+\left(\sqrt{x}+\sqrt{x+7}\right)-42=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\sqrt{x}+\sqrt{x+7}=6\\\sqrt{x}+\sqrt{x+7}=-7\left(vn\right)\end{matrix}\right.\)
\(\Leftrightarrow\left(\sqrt{x}+\sqrt{x+7}\right)^2=36\)
\(\Leftrightarrow2x+7+2\sqrt{x\left(x+7\right)}=36\)
\(\Leftrightarrow2\sqrt{x^2+7x}=29-2x\)
bình phương 2 vế
\(\Leftrightarrow4\left(x^2+7x\right)=4x^2-116x+841\)
\(\Leftrightarrow4x^2+28x=4x^2-116x+841\)
\(\Leftrightarrow144x=841\Leftrightarrow x=\dfrac{841}{144}\)
giải phương trình \(\sqrt{x}+\sqrt{x+7}+2\sqrt{x^2+7x}=35-2x\)
https://olm.vn/hoi-dap/question/595884.html
giải phương trình: \(\sqrt{x}+\sqrt{x+7}+2\sqrt{x^2+7x}=35-2x\)
ĐKXĐ: \(x\ge0\)
\(\Leftrightarrow2x+7+2\sqrt{x^2+7x}+\sqrt{x}+\sqrt{x+7}-42=0\)
Đặt \(\sqrt{x}+\sqrt{x+7}=t>0\)
\(\Rightarrow2x+7+2\sqrt{x^2+7x}=t^2\)
Pt trở thành:
\(t^2+t-42=0\Rightarrow\left[{}\begin{matrix}t=6\\t=-7\left(l\right)\end{matrix}\right.\)
\(\Rightarrow\sqrt{x}+\sqrt{x+7}=6\)
\(\Leftrightarrow2x+7+2\sqrt{x^2+7x}=36\)
\(\Leftrightarrow2\sqrt{x^2+7x}=29-2x\) (\(x\le\frac{29}{2}\))
\(\Leftrightarrow4\left(x^2+7x\right)=\left(29-2x\right)^2\)
\(\Leftrightarrow144x-841=0\Rightarrow x=\frac{841}{144}\)
gpt:
\(\sqrt{7x^2+25x+19}-\sqrt{x^2-2x-35}=7\sqrt{x+2}\)
Giải phương trình vô tỉ :
a) \(\sqrt{7x^2+25x+19}-\sqrt{x^2-2x-25}=7\sqrt{x+2}\)
b) \(\sqrt{4x^2+24x+35}-\sqrt{x^2+3x+2}=\sqrt{x^2+7x+12}\)
1)\(7\sqrt{3x-7}+\left(4x-7\right)\sqrt{7-x}=32\)
2)\(4x^2-11x+6=\left(x-1\right)\sqrt{2x^2-6x+6}\)
3)\(9+3\sqrt{x\left(3-2x\right)}=7\sqrt{x}+5\sqrt{3-2x}\)
4)\(\sqrt{2x^2+4x+7}=x^4+4x^3+3x^2-2x-7\)
5)\(\frac{6-2x}{\sqrt{5-x}}+\frac{6+2x}{\sqrt{5+x}}=\frac{8}{3}\)
6)\(2\left(5x-3\right)\sqrt{x+1}+\left(x+1\right)\sqrt{3-x}=3\left(5x+1\right)\)
7)\(\sqrt{7x+7}+\sqrt{7x-6}+2\sqrt{49x^2+7x-42}=181-14x\)
Giải phương trình \(\sqrt{x}\)+\(\sqrt{x+7}\)+\(\sqrt{x^2+7x}\)=35-2x
tìm x biết
\(2x^2+5x+8+\sqrt{x}=x^2+3x+35+x^2+2x-7\)
\(3\sqrt{x}+7x+5=\sqrt{x}+4x-6+3x+18\)
\(2\sqrt{3x}+11x-18=5x+2+6\cdot\sqrt{3x}+6x-21\)