[tex]\Large\boxed{\begin{array}{l}\sf 2x^2+12x+18=0\div2\\\sf x^2+6x+9=0\\\sf \Delta=b^2-4ac\\\sf\Delta=6^2-4\cdot1\cdot9\\\sf\Delta=36-36\\\sf\Delta=0\implies possui~uma~\acute unica~ra\acute iz~real\\\huge\boxed{\boxed{\boxed{\boxed{\sf\maltese~alternativa~a}}}}\end{array}}[/tex]
