[tex]zad.1\\\\2x+7=7\\\\2x=7-7\\\\2x=0~~\mid \div 2\\\\x=0~~\Rightarrow~~Odp:~~NIE\\\\zad.2\\\\x+2=x-2\\\\x-x=-2-2\\\\0\neq -4~~\Rightarrow~~x\in \oslash~~\Rightarrow~~Odp:~~TAK\\\\zad.3\\\\x+3=-x\\\\x+x=-3\\\\2x=-3~~\mid \div 2\\\\x=-1\frac{1}{2} ~~Odp:~~NIE\\\\zad.4\\\\3+x^{2} =19\\\\x^{2} +3-19=0\\\\x^{2} -16=0\\\\x^{2} -4^{2} =0\\\\(x-4)\cdot (x+4)=0\\\\x=4~~\lor~~x=-4~~\Rightarrow~~Odp:~~NIE\\\\[/tex]
[tex]zad.5\\\\x^{3} =-1\\\\x^{3} +1=0\\\\x^{3} +1^{3} =0\\\\(x+1)\cdot (x^{2} -x+1)=0\\\\x^{2} -x+1=0~~\lor~~x=-1\\\Delta=1-4=-3\\\Delta < 0~~\Rightarrow~~brak ~~pierwiastkow\\\\x=-1~~Odp:~~NIE[/tex]
