Because this is a positive parabola, it opens upwards, like a cup, and the vertex dictates what the minimum value of the function is. In order to determine the vertex, I recommend completing the square. Do that by first setting the function equal to 0 and then moving the 9 to the other side by subtraction. So far:

. Now, to complete the square, take half the linear term, square it, and add that number to both sides. Our linear term is 6. Half of 6 is 3 and 3 squared is 9. So add 9 to both sides.

. The right side reduces to 0, and the left side simplifies to the perfect square binomial we created while completing this process.

. Move the 0 back over and the vertex is clear now. It is (-3, 0). Therefore, 0 is the minimum point on your graph. The first choice above is the one you want.
Answer:
Amount of flour in the bag when Mary began = 
Step-by-step explanation:
Given:
Number of baked loaves of bread made from flour = 4
Number of muffins made from flour = 48
To find: Amount of flour in the bag when Mary began
Solution:
Let x denotes amount of flour used to make one baked loave of bread and y denotes amount of flour used to make one muffin.
So,
Amount of flour used to make 4 baked loaves of bread = 4 x
Amount of flour used to make 48 muffins = 48 y
Amount of flour in the bag when Mary began = 
The last option is the answer. You can double check by substituting the -3 for the x values and the 17 for y values and the statements would be true.
45 degrees! The angles of a triangle always add up to 180. The other two add up to 135. 180-135 is 45.