Answer:
3
Step-by-step explanation:
[tex]y = a(x - h) {}^{2} + k \\ \\ y = 3 {x}^{2} + 18x + 2 \\ y = 3( {x}^{2} + 6x + \frac{3}{2} ) \\ y = 3( {x}^{2} + 6x + {( \frac{3}{4} )}^{2} + \frac{3}{2} - {( \frac{3}{4} )}^{2} ) \\ y = 3 {(x + \frac{3}{4}) }^{2} + \frac{15}{16} [/tex]
