Resposta:
[tex]x=8[/tex]
Explicação passo-a-passo:
[tex]vou \ mostra \ duas \ formas \ diferentes \ de \ fazer:[/tex]
[tex]2x-4=12\\\\2x-4+4=12+4\\\\2x=16\\\\\frac{2x}{2} =\frac{16}{2} \\\\x=8[/tex]
[tex]2x-4=12\\\\2x-16=0\\\\x=\frac{-(-16)}{2} \\\\x=\frac{(2) \ . \ (-8)}{(2)} \\\\x=8[/tex]
