\(a,\sqrt{\left(x-1\right)^2-\left(x^2-3\right)}=3\)
\(\Leftrightarrow\left(x-1\right)^2-\left(x^2-3\right)=9\)
\(\Leftrightarrow x^2-2x+1-x^2+3=9\)
\(\Leftrightarrow4-2x=9\)
\(\Leftrightarrow x=\dfrac{-5}{2}\)
\(b,\dfrac{x+3}{x}+\dfrac{x-3}{x-2}=2\)
\(\Leftrightarrow\dfrac{\left(x-3\right)\left(2x-2\right)}{x\left(x-2\right)}=2\)
\(\Leftrightarrow\left(x-3\right)\left(2x-2\right)=2x\left(x-2\right)\)
\(\Leftrightarrow2x^2-8x+6=2x^2-4x\)
\(\Leftrightarrow-4x=-6\)
\(\Leftrightarrow x=1,5\)
a) \(\sqrt{(x-1)^{2}- x^2-3)}=3\)
\(\Leftrightarrow \sqrt{x^2-2x+1-x^2+3}=3\)
\(\Leftrightarrow \sqrt{4-2x}=3\)
\(\Leftrightarrow 4-2x = 9\)
\(\Leftrightarrow 2x=-5\)
\(\Leftrightarrow x=-2.5\)
Vậy S = {-2.5}
