Question

Janet is training for a marathon. She decides to track her time per mile, in minutes, for 8 weeks. Which equation best fits the data?

A graph is labeled as Marathon Training. The horizontal axis is labeled as Weeks and the vertical axis is labeled as Time per mile left parenthesis minutes right parenthesis. The values on the horizontal axis range from 0 to 10 in increments of 2 and the values on the vertical axis range from 0 to 10 in increments of 2. Nine points are marked on the graph with their coordinates approximately equal to (0, 10), (1, 9 decimal point 9), (2, 9 decimal point 6), (3, 9 decimal point 5), (4, 9 decimal point 4), (5, 9 decimal point 2), (6, 9), (7, 8 decimal point 7), and (8, 8 decimal point 6).
A.y=0.18x + 10.06
B.y=−0.18x + 10.06
C.y = 2x + 8.6
D.y = −2x + 8.6

I THINK ITS C AM I RIGHT

Answer 1

slope: (taking last two points); (yf-yi)/(xf-xi)= (8.6-10)/(8-0)=-1.4/8=-.18
intercept:
y=-.18x+ b using the point 0,10 then b=10

Answer 2

Janet takes 12 minutes to run around the track one time and george takes 8 minutes to run around the track. In how many minutes will they both be at the starting of the track at the same time?