To be able to compare the rates, we will write them in fraction form.
The fraction that represents Joe's rate is:

and the fraction that represents Bob's rate is:

Simplifying the above fractions, we get:

Since:

then Bob and Joe did not work at the same rate.
Answer:
No, Bob and Joe did not work at the same rate.
1. (0.5)2=1
2. (-0.2) + (-0.05) = -0.25
3. |-3 + 2.75| = 0.25
4. -(-0.25) = 0.25
5. 2x - 1.75x = 0.25x
So your answers are 3 and 4.
total mass = mass of a bag of candy + mass of a chocolate bar
total mass = 80g +110g = 190g
We know that this is a parabola, as the equation is denoted by the x^2 term.
We can see that the symmetry is seen at the point -0.5, therefore making the axis of symmetry the vertical line -0.5.
The vertex is found in quadrant three. In other words, it will shift by a negative value both horizontally and vertically. The vertex is therefore (-0.5, -0.5).
We can verify this in the equations by using the formula (-b/2a) to find the vertex. The only quadratic equation that satisfies this is -2x^2 + 2x -1.
To sum it up, the answers are:
-2x^2 + 2x - 1.
AoS: x = -0.5
Vertex: (-0.5, -0.5).