Respuesta :
Let flat rental fee be F
And per mile charge be M
We know that Bob drove 138 miles and was charged $112.96
And Carl drove 209 miles and was charged $142.78.
⇒ F + 138×M = 112.96 .............. (i)
And F + 209×M = 142.78 ................ (ii)
Subtracting (i) from (ii)
71×M = 29.82
⇒ M = 0.42
Substituting value of M in (i)
⇒ F + 138×0.42 = 112.96
⇒ F + 57.96 = 112.96
⇒ F = 55
So the fixed charge was $55 and the per mile charge was $0.42