Answer:
she has D=40, and Q=60
Step-by-step explanation:
X must be 4.
I uploaded the photo as an answer
The domain is the set of x values that has a corresponding y-values in a function or a graph.
The domain of the graph is: 
From the graph (see attachment), we have the following observation
- The value of x starts from -10 (represented by the horizontal line from (-10,4) to (-4,4))
- The value x ends at 10 (represented by the slant line on the first quadrant)
These values can be represented as:


So, the domain of x is: 
Read more about domain at:
brainly.com/question/24302079
That concentration would be
60 g
---------- = 60/300 = 1/5 (or, if you prefer, 1:5).
300 g
It is the blue one. By doing the vertex formula we can see the x value of the vertex is -3/4. The blue one best represents that as the negative A value shows the parabola will be facing down too and have a maximum not a minimum for the vertex