a)
\(2x+3=(2x+3)^2\)
\(\Leftrightarrow (2x+3)^2-(2x+3)=0\)
\(\Leftrightarrow (2x+3)(2x+3-1)=0\)
\(\Leftrightarrow (2x+3)(2x+2)=0\Rightarrow \left[\begin{matrix} 2x+3=0\\ 2x+2=0\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=-\frac{3}{2}\\ x=-1\end{matrix}\right.\)
b) \((x-5)^2=5-x\)
\(\Leftrightarrow (x-5)^2+(x-5)=0\)
\(\Leftrightarrow (x-5)(x-5+1)=0\)
\(\Leftrightarrow (x-5)(x-4)=0\)
\(\Rightarrow \left[\begin{matrix} x-5=0\\ x-4=0\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=5\\ x=4\end{matrix}\right.\)
c) \((x+2)^3=x+2\)
\(\Leftrightarrow (x+2)^3-(x+2)=0\)
\(\Leftrightarrow (x+2)[(x+2)^2-1]=0\)
\(\Leftrightarrow (x+2)(x+2-1)(x+2+1)=0\)
\(\Leftrightarrow (x+2)(x+1)(x+3)=0\)
\(\Rightarrow \left[\begin{matrix} x+2=0\\ x+1=0\\ x+3=0\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=-2\\ x=-1\\ x=-3\end{matrix}\right.\)
d)
\(|3x-1|=(1-3x)^2\)
\(\Leftrightarrow |3x-1|=|3x-1|^2\)
\(\Leftrightarrow |3x-1|^2-|3x-1|=0\)
\(\Leftrightarrow |3x-1|(|3x-1|-1)=0\)
\(\Rightarrow \left[\begin{matrix} |3x-1|=0\\ |3x-1|-1=0\end{matrix}\right.\Rightarrow \left[\begin{matrix} |3x-1|=0\\ |3x-1|=1\end{matrix}\right.\)
\(\Rightarrow \left[\begin{matrix} 3x-1=0\\ 3x-1=\pm 1\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=\frac{1}{3}\\ x=\frac{2}{3}\\ x=0\end{matrix}\right.\)
e)
\(2x+(x+3)(3-x)+(x+1)(x-1)=7\)
\(\Leftrightarrow 2x+(3^2-x^2)+(x^2-1^2)=7\)
\(\Leftrightarrow 2x=-1\Rightarrow x=-\frac{1}{2}\)
