#3 the answer is 4.
The reasoning for this is because x=-1 so if it is applied where x is at you have to subtract instead of multiplying in this equation. So 2xsquared is 2-1 which is 1. Same thing for 6x (6-1) which is 5. So the problem would end up being 1-5 which equals 4.
The vertex is at (4, -49) and the axis of symmetry is at x= 4.
To find the vertex of this equation, use this method:

a=2
b=-16
This will help get your x value and the axis of symmetry. To find the y value of the vertex, insert the x value, 4 to get your y value, -49.
The answer i got when i worked it out with my math teacher was C
Answer:
12 1/6
It wants me to add more but there's nothing to add
Answer:
AC=14
X=10
Y=1
Hoped this helped!
Step-by-step explanation:
DE is half of BC, therefore x=10. AE and EC have to be the same length, which is 7. SO, y=1 and x is 10.