Answer:
C. 81
Step-by-step explanation:
x^2-18x+81
(x-9)(x-9)
Answer:
-x -7
Step-by-step explanation:
(4x − 6) − (5x + 1)
Distribute the minus sign
(4x − 6) − 5x - 1
Combine like terms
4x-5x -6-1
-x -7
Let's first rewrite it in vertex form.
Start by completing the square.
y = x² + 4x + 4 - 4 - 1
y = (x + 2)² - 5
(x + 2)² = y + 5
Now, 4a = 1; a =

So, the vertex form is (x + 2)² = 4(

)(y + 5)
So, we know that the vertex is at (-2, -5).
Since it's a concave up parabola, we just have to change the y-value to find the focus.
∴ F(-2, -5 +

)
F(-2,

)