O GRAPHS AND FUNCTIONS Finding inputs and outputs of a two-step function that models a.. A railroad crew can lay 5 miles of track each day. They need to lay 145 miles of track. The length, L (in miles), that is left to lay after d days is given by the following function. L(d) = 145-5d Answer the following questions. (a) How many miles of track does the crew have left to lay after 17 days? miles (b) How many days will it take the crew to lay all the track? days X 5