Answer:
B
Step-by-step explanation:
I spent a lil time on it but I’ll let you know in a lil but if I have the answer:)
Hello :
y = 3x²+9x
= 3(x² + 3x )
= 3 ( x² +2(3/2)x +(3/2)²) -(3/2)²)
= 3((x+3/2)² -9/4)
y = 3 (x+3/2)² -27/4
<span>the x-coordinate of the vertex is : - 3/2</span>