đợt nọ my teacher làm như thế này:
vì \(x\ge-1\)nên \(\sqrt{x+1}\ge0\)
\(\sqrt{x+10}\ge3\)
\(VT\ge3\)
tương tự \(VF\ge3\)
nên VT=VT <=> x=-1
p/s:I don't sure about that
giai phuong trinh\(\dfrac{1}{x^2+4x+3}+\dfrac{1}{x^2+8x+15}+\dfrac{1}{x^2+12x+35}+\dfrac{1}{x^2+16x+63}=\dfrac{1}{5}\)
Giai phuong trinh
\(\sqrt{x+2+3\sqrt{2x-5}}+\sqrt{x-2-2\sqrt{2x-5}}=2\sqrt{2}\)
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 \(\left|x+2\right|^{2010}+\left|x+3\right|^{2011}=1\)
giai phuong trinh \(x^2+\sqrt{2-x}=2x^2\sqrt{2-x}\)
Giai phuong trinh: \(\sqrt{3x+x^2+\dfrac{9}{4}}+\sqrt{x^2+3x+1}=0\)
Giai phuong trinh:
\(\sqrt[3]{x+3}-\sqrt[3]{6-x}=1\)
Giai phuong trinh: \(\dfrac{2+\sqrt{x}}{\sqrt{2}+\sqrt{2+\sqrt{x}}}+\dfrac{2-\sqrt{x}}{\sqrt{2}-\sqrt{2-\sqrt{x}}}=\sqrt{2}\)
giai he phuong trinh\(\left\{{}\begin{matrix}x^2+y^2-xy=19\\x+y+xy=-7\end{matrix}\right.\)