Giai phuong trinh \(x\sqrt{x^2-x+1}+2\sqrt{3x+1}=x^2+x+3\)
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 ; 2\(\sqrt{x^2-x}-2\sqrt{x}\sqrt{2x-1}+3x=1\)
giai phuong trinh:\(^{x^2+3x-x\sqrt{x^2+2}=1+2\sqrt{x^2+2}.}\)
Giai phuong trinh va he phuong trinh:
a) \(\sqrt{x^2+6}=x-2\sqrt{x^2-1}\)
b) \(x^2+3x+1=\left(x+3\right).\sqrt{x^2+1}\)
c) \(\left\{{}\begin{matrix}x^2+y^2=11\\x+xy+y=3+4\sqrt{2}\end{matrix}\right.\)
Giai phuong trinh:
a) \(\sqrt{x^2+6}=x-2.\sqrt{x^2-1}\)
b) \(x^2+3x+1=\left(x+3\right).\sqrt{x^2+1}\)
b/ Đặt \(\sqrt{x^2+1}=a\ge0\)
\(\Rightarrow a^2+3x=\left(x+3\right)a\)
\(\Leftrightarrow\left(3-a\right)\left(x-a\right)=0\)
a/ Dựa vô TXĐ thì thấy \(x< 2\)
\(\Rightarrow\sqrt{x^2+6}+2\sqrt{x^2-1}-x>\sqrt{6}-2>0\)
Vậy vô nghiệm
alibaba nguyễn
b/ Đặt \sqrt{x^2+1}=a\ge0x2+1=a≥0
\Rightarrow a^2+3x=\left(x+3\right)a⇒a2+3x=(x+3)a
\Leftrightarrow\left(3-a\right)\left(x-a\right)=0⇔(3−a)(x−a)=0
a/ Dựa vô TXĐ thì thấy x< 2x<2
\Rightarrow\sqrt{x^2+6}+2\sqrt{x^2-1}-x>\sqrt{6}-2>0⇒x2+6+2x2−1−x>6−2>0
Vậy vô nghiệm
Giai phuong trinh: \(\sqrt{3x+x^2+\dfrac{9}{4}}+\sqrt{x^2+3x+1}=0\)
Lời giải:
Với mọi $x$ thuộc ĐKXĐ, ta luôn có:
\(\left\{\begin{matrix} \sqrt{3x+x^2+\frac{9}{4}}\geq 0\\ \sqrt{x^2+3x+1}\geq 0\end{matrix}\right.\)
Do đó, để \(\sqrt{3x+x^2+\frac{9}{4}}+\sqrt{x^2+3x+1}=0\) thì:
\(\left\{\begin{matrix} \sqrt{3x+x^2+\frac{9}{4}}= 0\\ \sqrt{x^2+3x+1}=0\end{matrix}\right.\)
\(\Leftrightarrow \left\{\begin{matrix} x=\frac{-3}{2}\\ x=\frac{3\pm \sqrt{5}}{2}\end{matrix}\right.\) (vô lý)
Do đó pt vô nghiệm.
Giai phuong trinh:
\(28+\sqrt[3]{x^2}=3x+2\sqrt[3]{x}+\left(x-4\right)\sqrt{x-7}\)
giai phuong trinh
a) \(\sqrt{3x^2-7x+3}-\sqrt{x^2-2}=\sqrt{3x^2-5x-1}-\sqrt{x^2-3x+4}\)
b) x2 - 25 = y ( y + 6 ) (x; y nguyên)
Giai phuong trinh \(\sqrt{x^3+15}+2=\sqrt{x^3+8}+3x\)
Em đã thử liên hợp nhưng cái ngoặc to xấu xí quá:(