Answer: 
Step-by-step explanation:
The missing figure is attached.
For this exercise it is important to remember that, by definition, the opposite interior angles of an inscribed quadrilateral are supplementary, which means that their sum is 180 degrees.
Based on this, you can identify that the angle D and the angle B are opposite and, therefore, supplementary.
Knowing that, you can write the following equation:

Now you must solve for "x" in order to find its value. This is:

Then:

You know that:

Therefore, since you know the value of "x", you can substitute it into
and then you must evaluate, in order to find the measure of the angle A. This is:

Go on the top right corner w the 3 dots
90? there’s a 45 degree angle at the bottom left and it looks like the same angle as x and y
Answer:
The parabola - quadratic.
Step-by-step explanation:
There is only graph / option in the picture but it is the correct one. Regardless, whether x is a positive or negative, the y coordinate is going to be a positive number as x^2 will produce a positive. So as -x^2 will also be positive.
Answer:
x = 350 gallons (amt of 60% solution that must be added)
Step-by-step explanation:
Amt of 60% solution = x gallons ; Amt of active ingredient = 0.6x gallons
Amt of 15% solution = 100 gallons ; Amt of active ingredient = 15 gallons
Amt of 50% solution = 100+x gallons ; Amt of active = 50 + 0.5x gallons
EQUATION:
Active ingredient: 0.60x + 15 = 50 + 0.50x
0.10x = 35
x = 350 gallons (amt of 60% solution that must be added)