[tex]12x^2-3x+9=(x-3)(x-5)\\12x^2-3x+9=x^2-5x-3x+15\\11x^2+5x-6=0\\11x^2+11x-6x-6=0\\11x(x+1)-6(x+1)=0\\(11x-6)(x+1)=0\\x=\dfrac{6}{11} \vee x=-1[/tex]
