Answer:
[tex] {2x}^{2} + 12x + 8 \\ = {x}^{2} + 6x + 4 \\ = {x}^{2} + 6x + {( \frac{6}{2}) }^{2} + 4 - {( \frac{6}{2} )}^{2} \\ = ( {x}^{2} + 6x + {3}^{2} ) + ( - 5) \\ = {(x + 3)}^{2} - 5[/tex]
