D
....................
........................
...........................
..............................
................................
.....................................
.......................................
........................................
..........................................
.............................................................
Answer:
198
Step-by-step explanation:
If you take any 3-digit number and change the numbers around and subtract them you will always get 198.
Assume Charles charges $7*3=$21 if he babysits for 2,5 hours (that is 2 and a half hours).
That is we are not considering Charles babysitting exactly 1, 2, 3 or 4 hours, but also in between times.
then we can write the following piecewise function to describe the situation:
f is a function from (0, 4] to {$7, $14, $21, $28}
The correct axis of symmetry is x = -1.
Explanation:
Our equation is

.
This is in vertex form, which is
y = a(x-h)² + k, where (h, k) is the vertex.
In our equation, h corresponds with -1 and k corresponds with -3, making the vertex (-1, -3).
The axis of symmetry is the x-coordinate of the vertex; this makes the axis of symmetry for this equation x = -1.