[tex]5)\\\\6x-4\neq 0\\\\6x\neq 4\ \ |:6\\\\x=\frac{4}{6}=\frac{2}{3}\\\\D=R\setminus\left\{\frac{2}{3} \right\}\\\\\\f(x)=\frac{4-9x^2}{6x-4}=\frac{ (2-3x)(2+3x) }{2(3x-2)}=\frac{- ( 3x-2)(2+3x) }{2(3x-2)}=\frac{- (2+3x) }{ 2}=\\\\=-\frac{2}{2}-\frac{3}{2}x=-\frac{3}{2}x-1[/tex]
[tex]6)\\\\ x^2-1\neq 0\ \ i\ \ x-1\neq 0\ \ i\ 2x\neq 0\\\\(x-1)(x+1)\neq 0\ \ i\ \ x\neq 1\ \ i\ \ x\neq 0\\\\x-1\neq 0\ \ i \ \ x+1\neq 0\\\\x\neq 1\ \ i\ \ x\neq -1\\\\D=R\setminus\left\{-1,0,1 \right\}[/tex]
[tex]\frac{ x^2+2x}{x-1} :\frac{2x}{ x^2-1} =0 \\\\\frac{ x^2+2x}{x-1} *\frac{ x^2-1}{2x} =0 \\\\\frac{ x(x +2 )}{x-1} *\frac{( x -1)(x+1)}{2x} =0 \\\\ \frac{ (x+2)( x+1) }{2} =0\\\\(x+2)(x+1)=0\\\\x+2=0\ \ lub\ \ x+1=0\\\\x=-2\ \ lub\ \ x=-1 \\\\x\in\left\{-2,-1 \right\}[/tex]
