[tex]1.\, x\in(-\infty,6\rangle\\x(-x+6)+2x=12\\-x^2+6x+2x-12=0\\x^2-8x+12=0\\x^2-2x-6x+12=0\\x(x-2)-6(x-2)=0\\(x-6)(x-2)=0\\x=6 \vee x=2\\\\(x=6 \vee x=2)\wedge x\in(-\infty,6\rangle\\x=2 \vee x=6\\\\2.\, x\in(6,\infty)\\x(x-6)+2x=12\\x^2-6x+2x-12=0\\x^2-4x-12=0\\x^2+2x-6x-12=0\\x(x+2)-6(x+2)=0\\(x-6)(x+2)=0\\x=6 \vee x=-2\\\\(x=6 \vee x=-2)\wedge x\in(6,\infty)\\x\in\emptyset[/tex]
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[tex]x=2 \vee x=6[/tex]
