If I know what you're asking, the answer is theoretical probability.
The axis of symmetry in a parabola is a line that's vertical that divides into 2 congruent halves.
18+ 13 gives you 31 so the difference between 13 and 31 is 18.
the answer is 31
Ed : (0,205)(4,197)
slope(m) = (197 - 205) / (4 - 0) = -8/4 = -2
y = mx + b
slope(m) = -2
(0,205)...x = 0 and y = 205
time to sub
205 = -2(0) + b
205 = b
equation is : y = -2x + 205...so Ed loses 2 lbs per week
Eric :
y = -1.5x + 200...so Eric loses 1.5 lbs per week
when they started, Ed weighed 205 lbs and Eric weighed 200 lbs
* of the two, Eric loses fewer lbs per week. When the two began their respective weight-loss programs, Ed was heavier by 5 lbs.
