a)
pA(x) = (60 - 35)/(80 - 30)·(x - 30) + 35 = 0.5·x + 20
pN(x) = (60 - 35)/(30 - 105)·(x - 105) + 35 = 70 - x/3
xA(p) = 2·p - 40
xN(p) = 210 - 3·p
b)
xA(p) = xN(p)
2·p - 40 = 210 - 3·p
5·p = 250 --> p = 50 GE
xA(50) = 2·50 - 40 = 60 ME
c)
xA(55) - xN(55) = (2·55 - 40) - (210 - 3·55) = 25 ME
d)
xN(40) - xA(40) = (210 - 3·40) - (2·40 - 40) = 50 ME