Answer:
Step-by-step explanation:
-2y-4=4y-4
2) cancel 4 out on both sides
-2y=4y
3) divide both sides by -2
y=-2y
4) subtract both sides by -2y
y+2y=0
5)3y=0
6) divide by 3
Y=0
This type of essay answer is pretty short.
You play out the equation and say what each part of the equation means. The vertex in this case, because it's a downward facing parabola, is the highest point on the graph. Now since they're kicking a ball, the vertex will be the highest point that the ball will go up to.
Hopefully this helps some. For full points you'll probably have to add a bit of padding and further explanation.