900 because 9 is greater than 5 so it rounds to my answer.
Answer:
12
Step-by-step explanation:

There are 2 roots so the only way to complete the square is,
![y=2x^2+8x-9\\y=2[(x^2+4x)]-9\\y=2[(x^2+4x+4)-4]-9\\y=2[(x+2)^2-4]-9\\y=2(x+2)^2-8-9\\y=2(x+2)^2-17](https://tex.z-dn.net/?f=y%3D2x%5E2%2B8x-9%5C%5Cy%3D2%5B%28x%5E2%2B4x%29%5D-9%5C%5Cy%3D2%5B%28x%5E2%2B4x%2B4%29-4%5D-9%5C%5Cy%3D2%5B%28x%2B2%29%5E2-4%5D-9%5C%5Cy%3D2%28x%2B2%29%5E2-8-9%5C%5Cy%3D2%28x%2B2%29%5E2-17)
Just factor 2 out of 2x^2+8x (just ignore the -9) then find the number that will make the terms be able to complete the square.
then complete the square and multiply 2 inside the brackets.
subtraction as you already get the vertex form and know how to complete the square.
Vertex Form: 
Answer:
X = 5
Step-by-step explanation:
Here is what I am picturing (not to scale)
A ----------------B-----------C
We are given the information of AB (which equals 3x + 1), BC (which equals 4x - 5), and AC (which equals 8x - 9).
With reference to the line, AB + BC = AC
So,
3x + 1 + 4x - 5 = 8x - 9
7x - 4 = 8x - 9
5 = x
Sure What do u need help with I am always here