Question

(I WILL GIVE BRAINLIEST)

Answer 1

For this case we have the following polynomial:

$3x ^ 2 + 9x + 15$

The standard form of the polynomial is given by:

$ax ^ 2 + bx + c$

Where, the axis of symmetry of the polynomial is given by the expression:

$x = - \frac {b} {2a}$}

In this case we have:

$a = 3\\b = 9$

Therefore, replacing values we have:

$x = - \frac {9} {2 (3)}$

Rewriting we have:

$x = - \frac {9} {6}\\x = - \frac {3} {2}$

Answer:

The symmetry axis of the polynomial is given by:

$x = - \frac {3} {2}$

option C