Respuesta :

y=x+35 x is miles in 20 mile increments
Let x represent the number of miles travelled and y the cost. Then
y - 46 = (46 - 40)/(220 - 100) (x - 100)
y - 46 = 6/120 (x - 100)
y - 46 = 1/20(x - 100)
20(y - 46) = x - 100
20y - 920 = x - 100
x - 20y = -820