[tex]6(2-7x)+x(7x-2)=0[/tex]
Use distributive property: a(b - c) = ab - ac
[tex](6)(2)-(6)(7x)+(x)(7x)-(x)(2)=0\\\\12-42x+7x^2-2x=0\\\\7x^2-44x+12=0\\\\7x^2-42x-2x+12=0\\\\7x(x-6)-2(x-6)=0\\\\(x-6)(7x-2)=0\iff x-6=0\ \vee\ 7x-2=0\\\\x-6=0\ \ \ |+6\\\\x=6\\\\7x-2=0\ \ \ |+2\\\\7x=2\ \ \ |:7\\\\x=\dfrac{2}{7}[/tex]
Answer:\ [tex]x=6\ \vee\ x=\dfrac{2}{7}[/tex]