6/42 = n/7
Multiply by 7.
42/42 = n.
n = 1.
numerator = 42.
1. (16,25)-(24,5) the interval it falls from is 25 mph to 5 mph or it decreased by 20 mph.
2. From D (24,5) to E (28,45). The interval of time from point D to point E is 5 mph to 45 mph. or it increased by 40 mph.
3. From B (6,25) to C (16,25) and the constant rate is 25 MPH.
I'm not 100% sure about the everything.
About $0.48
you can make an equation
12/5.79 = 1/x
So, parallel lines have the same slope, therefore a parallel line to 2x+12, will have the same slope as that one, so which is it?

so, we're really looking for the equation of a line whose slope is 2, and runs through -1,1.